Fertilize or not. It’s up to you? Genetically Controlled Self-Incompatibility in Plants

You might wonder why I named this article “Fertilize or not? It’s up to you”. It’s because plants have the ability not to fertilize even though the mature pollen falls onto mature stigma. Self-fertilization may occur in hermaphrodite (bisexual) plants and self-fertility might be beneficial for plants. However, plants also have developed mechanisms to prevent self-fertilization, which can lead to inbreeding depression. Higher plants which are mostly hermaphrodite can assure reproduction through cross-fertilization. Self-incompatible plants increase outbreeding and retain genetic variety, which is thought to be crucial in the evolution of flowering plants.
Self-incompatibility is essentially a carefully regulated genetic system that offers a highly selective detection and rejection system for pollen that is genetically similar to the pollen of the same plant. Darwin initially identified heteromorphic Self-incompatible systems, which use blooms with diverse morphs (e.g. distyly in Primula), but they have not been adequately studied and defined at the molecular level. Self-incompatibility provides a clever genetic mechanism for avoiding self-fertilization. S-determinant genes, which allow self-recognition and rejection, determine self-incompatibility. Several S-determinant genes have been discovered in various plants. A highly polymorphic, multiallelic S-locus is responsible for homomorphic Self incompatibility. It has been calculated that natural populations of a single species may have up to 30 to 60 alleles. As it is maintained, this polymorphism has been the topic of several populations of genetics research in the modern world.
There are mainly two types of self-incompatibility in plants. They are gametophytic self-incompatibility (GSI) and Sporophytic self-incompatibility (SSI). In Gametophytic self-incompatibility when the solitary S allele contained in the haploid pollen grain matches either of the S alleles present in the diploid tissues of the pistil, pollen is rejected. This is due to the detection of some proteins in pollens by the receptors in the stigma of the flowers. Some examples of plants that show gametophytic self-incompatibility are ornamental tobacco (Nicotiana alata), petunia (Petunia inflata and Petunia hybrida), potato (Solanum tuberosum and Solanum chacoense), and wild tomato (Lycopersicon peruvianum). In Sporophytic self-incompatibility systems, rejection is controlled by the interaction of the pistil’s self-incompatibility genotype with the genotype of the pollen parent, rather than the pollen’s haploid genotype, as in the gametophytic system. In plants with sporophytic self-incompatibility, each pollen grain contains the products of two S alleles, and rejection occurs when either of these alleles matches either of the S alleles expressed in the pistil; complex dominant or codominant interactions between S alleles frequently occur, influencing the outcome of specific crosses.

Figure 1 - Homomorphic self-incompatibility systems

Figure 1 - Homomorphic self-incompatibility systems

This amazing mechanism in plants has saved plants from genetic disorders and many other genetic disadvantages. Thus, self-incompatibility has provided a great evolutionary advantage to plants.

References:
Matton, D. P., Nass, N., Clarke, A. E., & Newbigin, E. (1994). Self-incompatibility: How plants avoid illegitimate offspring. Proceedings of the National Academy of Sciences of the United States of America, 91(6), 1992–1997. https://doi.org/10.1073/pnas.91.6.1992

Image courtesy:

Featured Image:
https://www.flickr.com/photos/30232567@N05/8124026433

Figure 1
https://dfzljdn9uc3pi.cloudfront.net/2017/4085/1/fig-1-2x.jpg

Gene Prediction in Bioinformatics

Generally, it is difficult to carry out conventional experiments on living cells to predict genes. But today, bioinformatics research is making it possible to predict the functions of a gene, based on its sequence alone. The DNA databases that are cropping up with many DNA sequences around the world facilitate the gene prediction process intensively. Have you ever wondered about Gene Prediction? It is the process of identifying potential coding regions in an uncharacterized region of the genome. Simply it means locating genes along a genome.
Prediction of genes to find the location of protein-coding regions is now an active research field in bioinformatics. Genes are not the only thing looked for in this process, but also splice sites, protein binding sites and DNA 3D structural features. Gene finding is specific to each species, therefore, functional regions may vary by species. Moreover, the common repeat sequence information is considered in gene-finding programs to identify coding regions.
Gene finding is less difficult in prokaryotic genomes due to the absence of introns in the protein-coding genes. Introns do not code for any functional protein but exist between functional regions(exons), which are usually responsible for protein synthesis. Eukaryotic gene prediction is a more complex problem as the genomes are much larger than prokaryotic genomes and also they tend to have a very low gene density. For example, in humans, only 3% of the genome codes for genes. Moreover, the identification of exons and introns has made it difficult for gene prediction.
When discussing the methods of gene prediction, similarity-based searches and ab-initio predictions are important. Sequence similarity search is based on finding similarities in gene sequences between ESTs (Expressed Sequence Tags) and proteins. When a similarity between a certain genomic region and an EST, DNA, or protein is discovered, the similarity information can be used to infer the gene structure or function of that region. Local alignment and global alignment methods are used in this type of search. The most common tool used is BLAST and it detects sequence similarity to known genes. Software such as PROCRUSTES and GeneWise use the global alignment method for gene prediction.
Ab-initio methods use gene structure as a template to detect genes and it is a computational task. Many algorithms are applied in ab-initio methods for modeling gene structure, such as Dynamic Programming, Hidden Markov Model and Neural Network. Based on these models, many gene prediction programs have been developed such as FGENESH, GeneParser, GlimmerM and GENSCAN.

Even though there are many gene prediction programs, the accuracy and reliability of the algorithms used must be considered as well when using such programs. Furthermore, comprehensive criteria are required to evaluate gene prediction programs. One of the main drawbacks is that it is still difficult to locate short exons in genes, therefore the performance of algorithms for recognizing short coding sequences is quite low. Other challenges involved in gene prediction are sequencing errors in raw DNA data, dependence on the quality of the sequence assembly, handling short reads, frameshift mutations, overlapping genes and incomplete genes.
Since the outcome of the gene prediction approach is quite essential in transcriptomics, proteomics and genome studies, it requires great effort in both computational and experimental methods to make gene prediction more accurate. This will in turn reduce the amount of experimental verification work required significantly. With rapid advances in computational techniques and understanding of the splicing mechanism, it is hoped that reliable eukaryotic gene prediction can become more feasible in the upcoming future.

References:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5187414/
https://www.sciencedirect.com/topics/medicine-and-dentistry/gene-prediction

Image courtesy:
Featured image:
https://www.sciencemag.org/news/2018/09/there-are-about-20000-human-genes-so-why-do-scientists-only-study-small-fraction-them

Figure 1:
https://www.slideserve.com/gomer/gene-finding-and-gene-structure-prediction

A story of a never-ending fight

Scientists asked a highly virulent microbe, what made you this tough? Here is the answer. Microorganisms including fungi, bacteria, viruses, molecules as well as nematodes can become pathogenic to plants. The ability to cause a disease or pathogenicity depends on the virulence of the pathogen, host resistance and environmental conditions. Pathogenesis helps pathogens to invade plant tissues to obtain nutrients for their survival and reproduction. Nature has given pathogens their “level of virulence” in this survival-based interaction that requires for the infection while plants were given their “range of defense”.

Back in the evolutionary time scale, plants and their special parts have evolved to provide at least room and board to many microorganisms, enabling them to fulfill their functions. As a result of this long-lasting process, some microbes might have evolved to interfere with the physiological function of plants due to the mutations favoured by natural selection. Then plants obviously might have had to react through responsive mutations related to their defense against those microbes.

Plants protect themselves as a result of molecular, cellular and tissue responses. These defenses can be either structural or chemical. Plants might have first tried their best to safeguard themselves using basic physical and chemical barriers as a form of passive defense. This can be pre-existing structural barriers such as wax, hairs, cuticle, epidermis, the orientation of leaves and the nature of stomata. Plants are well armed with pre-existing chemical defenses as well. They release inhibitors such as fungal toxic exudates to inhibit spore germination and some of these inhibitors are present in plant cells, for example, phenolics, tannins, saponins and lectins. Moreover, some plants lack receptors for toxins and some lack essential substances for pathogens.

Plants have further developed another level of defense called active defense, literally the immune system of plants. Plants can detect the presence of infectious agents through signals. These signalling molecules perceived by plant cells to induce defense responses are called elicitors. Elicitors can be specific or nonspecific. Nonspecific elicitors such as pathogen-associated molecular patterns (PAMPs) have a kind of evolutionary stability.  These elicitors can induce defense in a wide range of host species. They are originated from pathogenic organisms. These are sensed through pattern recognition receptors (PRRs) on the surface of the plant cells, which would trigger the basal resistance called PAMP triggered immunity (PTI), but still, there could be better fighters!

The pathogens which successfully overcome basal resistance would produce effector proteins, which could inhibit signalling pathways mediated by basal immunity. Thus, they become specific elicitors, if the host plant manages to recognize them. Specific elicitors are produced by specialized pathogenic strains that match the receptors of the specific host cultivar. These effector proteins are encoded by avirulence genes (Avr genes) of pathogens. If the host plant has specific receptors to bind to those effectors, then effector-triggered immunity (ETI) will occur within the plant.  The resistance genes (R genes) are required to encode for these receptors, and not all hosts can produce such genes.

Figure 1: PTI and ETI (Hypersensitive response)

Figure 1: PTI and ETI (Hypersensitive response)

This never-ending race between pathogen and their host plants along the evolutionary pathway was proven through the ‘gene for gene concept’ by H.H. Flor in 1956. According to the theory, the host plants and their pathogens have evolved together. It further states that any change in the pathogen virulence is balanced by the evolutionary change in host resistance and this dynamic equilibrium is maintained by the step wise evolution. So, isn’t it a never-ending fight? Each opponent makes the other stronger in this battle while walking along the evolutionary pathway.

References:
https://oajournals.fupress.net/index.php/pm/article/view/5543

https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1009175

Image courtesy:
Featured image:
https://www.britannica.com/list/botanical-barbarity-9-plant-defense mechanisms
Figure 1:
https://media.springernature.com/original/springer-static/image/chp%3A10.1007%2F978-981-10-2854-0_12/MediaObjects/417622_1_En_12_Fig1_HTML.gif

The world’s most expensive coffee

Coffee is produced by an evergreen plant species named Coffea canephora, which belongs to the family Rubiaceae. These species are native to Southern Africa and tropical Asia. Coffee is one of the most popular beverages among everyone. It is prepared in many different ways all over the world. Have you ever tried the world’s most expensive coffee product? Go ahead and you will find out more about it.
‘Kopi Luwak’ is the most expensive coffee which is made from a unique natural fermentation method. A cup of this coffee usually costs approximately $30- $100. As you can see, it is way more expensive than an average coffee.

Figure 1 – Asian Palm Civet which produces ‘Kopi Luwak’

Figure 1 – Asian Palm Civet which produces ‘Kopi Luwak’

The history of ‘kopi luwak’ runs back to the 1700s when Dutch introduced coffee for the first time in Sumatra and Java. Those days, harvesting coffee was prohibited to people, but they noticed civets eating coffee cherries and leaving coffee beans behind. Then, they started brewing coffee from these beans taken from the discards of civets.
When the coffee cherries are eaten by Asian Palm Civets, they are partially digested by the digestive enzymes found in the civets’ digestive systems. This causes a change in the protein structure of coffee beans and reduces acidity, which ultimately helps to make a smooth cup of coffee. During the process, workers in coffee plantations handpick the lightly fermented coffee beans from the droppings. These beans are cleaned, dried, and roasted at the end. Roasting helps to develop the aroma, colour and flavour of the coffee.

Figure 2 – Coffee beans extracted from civet droppings.

Figure 2 – Coffee beans extracted from civet droppings.

‘Kopi luwak’ can be produced from both free wild civet poop and caged civet poop. Unfortunately, the production of wild civet coffee is labour-intensive, hence most of the coffee is made using caged civet poop, but this process does not happen ethically. They do not maintain proper hygiene, mobility of animals and safety methods in those cages. Civets are shy, nocturnal animals, and foreign visits to coffee plantations disturb their natural behaviours. Also, these caged civets are often fed with coffee cherries as the only diet, which could lead to malnutrition and other health problems. With the rising popularity of coffee, many civets are being removed from the wild and caged to produce large amounts of ‘kopi luwak.’ This would badly affect the interactions between the civets as well.

Figure 3 – Captive civets for kopi luwak production

Figure 3 – Captive civets for kopi luwak production

Now, you know how the world’s most expensive coffee is made. But did you know that it is really hard to separate wild civet coffee from caged civet coffee? The only way to find out is by taste. Caged civet coffee has an inferior taste and acidity while free wild coffee has a better-quality taste. However, if you want to try a cup of this coffee, there are companies that would provide ethical wild civet ‘kopi luwak’. You can try it yourself for an authentic taste of coffee.

Image courtesy –
Featured image – https://thursdaydinners.com/all-you-need-to-know-about-kopi-luwak-coffee/

Figure 1 – https://food-contact-surfaces.com/2017/08/worlds-most-expensive-coffee/

Figure 2 – https://www.coffeedesk.com/blog/kopi-luwak-is-it-really-the-best-coffee-in-the-world/

Figure 3- https://news.mongabay.com/2016/05/worlds-expensive-coffee-often-produced-caged-abused-civets-study-finds/

References –

https://www.nationalgeographic.com/animals/article/160429-kopi-luwak-captive-civet-coffee-Indonesia

https://coffeeaffection.com/kopi-luwak/

World’s most expensive coffee often produced from caged, abused civets, study finds

How do plants recognize seasonal changes?

Seasonal change is a common phenomenon in temperate regional countries. Plants get new looks during every new season. Have you ever wondered how plants recognize and change according to these seasons? After reading this article, you will be able to find the answer to this question.

As we already know, there are four major seasons named spring, summer, autumn, and winter. Seasonal changes can be described as the differences in temperature and the hours of getting daylight during a year. Therefore, it relates to changes in day and night lengths. These changes occur due to the Earth’s movement around the sun and the tilted rotational axis of the Earth. It allows some parts of the Earth to get direct sunlight and the other parts to get less sunlight and heat. Furthermore, the parts getting most of the direct sunlight and heat will have spring and summer, while other parts have autumn and winter. In summer, daylight lasts longer, and nights are short whereas in winter, days are shorts and nights are long.

According to seasonal changes, plants change their appearance by blooming, flowering, shedding, and becoming dormant. In spring, flowers start to bloom, and trees have young leaves and flowers. They have mature leaves and flowers during summer. They get tall, bear fruits, and most of their growth happens during this season. In autumn, their leaves become brown and shed. Since winter is colder and gets less sunlight compared to the other seasons, plants tend to stay dormant without any leaves, flowers, or fruits.

Figure 1: Leaves turn brown and shed during autumn

Figure 1: Leaves turn brown and shed during autumn

How do they decide to change as above at the correct time? Unlike us, they do not have clocks or calendars! The main reason is that plants are composed of light-detectors called photoreceptors. There are two types of photoreceptors in plants, and they are phytochromes and cryptochromes. Phytochromes are sensitive to the red and far-red region of the visible spectrum, whereas cryptochromes are sensitive to the blue region. The amount of the receiving light can be detected by those receptors.

During shorter days (daytime is less), they identify that there is less sunlight to be obtained and change accordingly. This response, according to the length of day and night, was described by the word photoperiodism. In other words, photoperiodism is showing responses to the length of day or night by organisms. This fascinating discovery was done by W. W. Garner and H. A. Allard in 1920. Different plants have different photoperiods. Some plants prefer more daylight, while others prefer less daylight.

Figure 2: Plants remain dormant during winter

Figure 2: Plants remain dormant during winter

The best-described example of photoperiodism is the flowering of plants. Most plants recognize the length of the dark period which is critical for the initiation of flowering. When a plant reaches its critical photoperiod by receiving an appropriate length of night period, it acts as a stimulus and starts flowering as a response. Based on photoperiod, plants can be classified into three categories. They are long-day plants, short-day plants, and day-neutral plants. When the length of night exceeds its critical photoperiod, some plants start flowering. Those plants are called short-day plants. Plants that start flowering when the length of night is less than their critical photoperiod are called long-day plants. However, some plants do not respond to photoperiod at all. Those plants are named day-neutral plants.

Now you know how plants get new looks during every new season at the correct time. By perceiving light signals via phytochromes or cryptochromes, plants undergo this amazing phenomenon called photoperiodism. They bloom, flower, shed, and become dormant in this astonishing world based on the season! Isn’t it amazing?

References:
https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/photoperiodism

https://www.happysprout.com/inspiration/seasons-plant/#:~:text=These%20amazing%20seasonal%20changes%20in,temperature%20also%20plays%20a%20role.

https://www.britannica.com/science/photoperiodism

http://www.biologyreference.com/Ph-Po/Photoperiodism.html

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Featured image: https://bit.ly/3xqXuak

Figure 1: https://bit.ly/3cXTzKc

Figure 2: https://bit.ly/3gOMflb

Green over Grey

Have you heard about green buildings? If yes, what comes to your mind when picturing a green building? Most probably it would be a building with some green plants placed here and there, wouldn’t it? Is that all within the meaning of green building? Go ahead to find the answer!

The impact on the environment has increased with the increasing population and the development of the world. From design to construction and operation of a building, it consumes a lot of natural resources. The green buildings are designed with efficient use of energy, water and other resources, protection of occupant health, improvement of employee productivity, reduction of waste and pollution etc. Therefore, the concept of green building is not limited to the walls but includes site planning, community and land-use planning. This concept is very important for the sustainable development of the world.

Simply a green building can be described as a building that is designed in a way to protect the natural environment and to improve the quality of life as well. A green building is further defined as a building that, in its design, construction or operation, reduces or eliminates negative impacts, and can create positive impacts, on our climate and natural environment.

As the word ‘green building’ itself shows, they are eco-friendly having various benefits to the environment. Improving air and water quality, reducing waste streams, conserving and restoring natural resources, reducing the urban heat island effect, and enhancing biodiversity and ecosystems are some of those benefits. In addition to the environmental benefits, green buildings provide economic and social benefits. The economic benefits of green buildings are reducing operating costs, improving occupant productivity, and enhancing asset value and profits. There are social benefits such as enhancing occupant health and comfort, improving indoor and air quality and improving the overall quality of life. Most importantly green buildings fulfil 9 SDGs (Sustainable Development Goals) out of the 17 indicating the importance of having more green for a sustainable earth. However, there are still some hurdles such as the higher initial design and construction cost and lack of public awareness.

Figure 1: The green building concept

Figure 1: The green building concept

Sustainable building design relies on six fundamental principles. Optimizing site potential, optimizing energy use, efficient use and conserving water, optimizing building space and material use, enhancing indoor environmental quality and optimizing operational and maintenance practices. It is always considered to be more environmentally friendly through the whole process from planning the design to operation of the building under these principles. It does not matter whether it’s a school, an office, a shop, a hotel or even a hospital or any other type of structure. It can be a green building if it follows the above-mentioned principles. The methods which are used to follow these fundamental principles can be changed among countries depending on the climatic conditions, environmental, economic and social priorities, unique cultures and traditions, available technologies etc.

Who would not love to be in a city with more green and less pollution? Let’s always try to go green and make the city we live in, the city we love!

Weight loss journey with gut bacteria

Overweight is the major problem in today’s human population. The major reason for increasing overweight in the world is energy imbalance between calories consumed and calories expended due to increased intake of energy dense foods that are high in sugar and fat level and increased physical inactivity. The worldwide prevalence of obesity nearly tripled between 1975 and 2016. Some recent WHO global estimates follow,
In 2016,

  • More than 1.9 billion adults aged 18 years and older were overweight and of these over 650 million adults were obese.
  • 39% of adults aged 18 years and over (39% of men and 40% of women) were overweight.
  • Overall, about 13% of the world’s adult population (11% of men and 15% of women) were obese in 2016.

In 2019,

  • 38.2 million children under the age of 5 years were overweight or obese.

Overweight is major risk factor for several noncommunicable diseases such as cardiovascular disease like stroke and heart disease, diabetes, musculoskeletal disorders especially osteoarthritis and cancers associated with endometrial, breast, ovarian, prostate, liver, gallbladder, kidney, and colon.

Can gut bacteria be used to get rid of overweight? it is yes, it is most beneficial to the human population. Everyone knows there are several microorganisms associated with our gut. They are not having skinny or fat bacteria like this. But some microorganisms in your gut may help to maintain body shape and hold the answer to why some people prevent obesity. Human intestine contains trillions of mutually beneficial microorganisms and They create ecosystems that contract with functions like metabolism, hunger, and digestion. Those microbial communities perform various jobs in the colon, and they help to control metabolism other terms they affect the weight of the body. Some situations like the intestinal environment are imbalanced, that is affected for those microbial communities. In that situation lowering the number of beneficial ones and increased number of opportunistic pathogens or reduced diversity of gut microbiota. That situation is called ‘dysbiosis’. That can have an impact on the human body as well as health. That causes people to easily become overweight.

How does gut microbiota help for weight loss? They break down dietary fiber and turn it into short- chain fatty acid. That fatty acids have several functions like anti-inflammatory functions, maintaining healthy gut lining, regulating metabolism and food intake. Loss of some short-chain fatty acids like butyrate increases eating due to hunger that causes high blood sugar and insulin resistance. Some probiotics are inhibiting the absorption of dietary fat and increasing the amount of fat excreted. Some are fight with obesity by releasing appetite regulating hormones and increasing level of fat regulating proteins. Appetite regulation hormones are increased calories and fat burning rate. The fat regulating proteins are decreased fat storage.

figure 01

figure 01

Who are the bacteria influenced with body weight? that is very important. There are two types of gut bacteria associated with lean body weight. Akkermansia muciniphila and Christensenella minuta are those two bacteria who lean with loss of body weight because they are linked with preventing weight gain and found in slim individuals.
Akkermansia muciniphila feed on the mucus that lines the gut, and they are promoting the production which strengthens the intestinal barrier, the strong intestinal barrier prevents obesity. They also produce acetate; it is short chain fatty acid that regulates body fat stores and appetite. Abundance of A. muciniphila can be tried boost using prebiotic foods that fuel for their activities. Increasing intake of that kind of food helps to the growth of A. muciniphila in the gut and enhances protection against obesity. Cranberries, concord grapes, black tea, fish oil, bamboo shoots, flaxseeds, rhubarb extract are the best food to boost the abundance of those organisms.
Christensenella minuta that is the bacterium abundantly found in a skinny individual’s gut then scientists think they help to prevent obesity. Some people have them and some have not because it depends on genetic makeup of individuals.

figure 02

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How to increase gut microbiota for weight loss? The gut microbial health is influenced by the lifestyle of humans. The food and exercise also play critical roles for the diversity of gut microbiota and plant-based food and healthy fats help for their health- promoting services. The fiber contains plant food with different colour also helps to increase the diversity of gut microbiota. Considering lifestyle, physically active humans have balanced gut microbiota more than others.

Aerobic exercises like walking, jogging, swimming, cycling, and dancing the ones that get increased heart pumping increase the abundance of that kind of health promoting bacteria like Bifidobacterium, Faecalibacterium prausnitzii and A. muciniphila. That helps to reduce risk of dysbiosis that are associated with being overweight. Red colour foods such as apples, tomatoes, red onion etc. , yellow colour foods such as banana, corn etc., orange colour foods such as mangoes, turmeric etc., ,green colour foods such as green tea, cabbage etc., and purple colour foods such as blueberries, purple grapes etc. , are the foods help for maintain balanced gut microbiota for weight loss. The scientist said, “eat rainbow to prevent obesity and get a healthy life”. The lots of research that shows long term weight gain is associated with imbalance of gut microbiota due to lack consuming fibrous foods. There is not any supplement of microbiota for increased beneficial gut microorganisms it can be only done by intake of lots of vegetables, fruits, whole grains, nuts and seeds, polyphenol rich foods such as dark chocolate, green tea, fermented food such as yogurt, kefir, and prebiotic fibers.
What are the factors affect for decrease beneficial gut microbiota? The most critical factor for dysbiosis is high levels of sugar and fats. The intake of antibiotics also reason for imbalance of gut microbiota because they disrupt microbial communities in gut and slow down growth rate or killing them also. Some research that shows intake of antibiotics indirectly affect for world obesity problem. Less intake of sugar, artificial sweetness and meat is very important to maintain gut microbiota. Sugary foods stimulate the growth of certain unhealthy bacteria in gut, and they influence for overweight. Artificial sweeteners like aspartame and saccharin reduce beneficial microbes in gut. Unhealthy fats help to grow disease causing bacteria to affect the disbalancing of gut microbiota.

Finally, all may know, all have unique gut microbiomes. The diversity of gut microbiomes depends on a person’s lifestyle. The main thing you must understand is not having weight loss microbes, but they indirectly help for losing body weight using their products and functions mentioned below.

References:
https://www.who.int/news-room/fact-sheets/detail/obesity-and-overweight
https://www.who.int/news-room/fact-sheets/detail/obesity-and-overweight
Cani, P, D and de Vos, W, M., Next-Generation Beneficial Microbes: The Case of Akkermansia muciniphila, 2017
Hold, G, L., The Gut Microbiota, Dietary Extremes and Exercise. 2014
Menni, C et al., Gut Microbiome Diversity and High-Fiber Intake Are Related to Lower Long-Term Weight Gain., 2017
Zhou, K., Strategies to Promote Abundance of Akkermansia muciniphila, 2017
https://atlasbiomed.com
Image courtesy:
Featured image : https://www.torqfitness.co.uk/news/performance-weight-loss
Figure 1 : https://kids.frontiersin.org/article/10.3389/frym.2017.00035
Figure 2 : https://medicalxpress.com/news/2021-02-gut-microbiome-implicated-healthy-aging.html

Role of microorganism in development of vaccines

There are many diseases caused by microorganisms. They can be viruses, bacteria, fungi or any other microorganisms. Pathogens are microorganisms that have the potential to cause diseases. An infection of a pathogen does not always result in a disease. The infection is a process that can be seen as a battle between the invading pathogens and the host. Our bodies are equipped to fight off invading pathogens and that may prevent diseases. It is called natural defence. When the invading pathogen has the ability to overcome the host's natural defence, it will make disease on the host.
Vaccination is an effective and safe way of protecting people against harmful diseases. It uses the body's natural defence to build resistance to specific infections and makes peoples’ immune system stronger. Vaccines consist of dead or inactivated microorganisms or the purified products of microorganisms. When scientists create vaccines, they consider how the host immune system responds to the pathogen, which needs to be vaccinated against the pathogen and the best technology or approach to create a vaccine.
There are four types of conventional vaccines. They are,

  • Inactivated vaccines
  • Live attenuated vaccines
  • Toxoid vaccines
  • Subunit vaccines.

Inactivated vaccines for a disease are developed using killed microorganisms which are causing the same disease. These microorganisms can be killed using heat or chemicals. These inactivated vaccines do not provide immunity as strong as live vaccines. So people may need to get vaccinated several doses over time against ongoing diseases. Inactivated vaccines are used to protect against Hepatitis A, Flu, Polio, and Rabies.
Live-attenuated vaccines are developed using living microorganisms by suppressing their harmful properties or by using related harmless organisms. These vaccines are more similar to natural infection. These are the most beneficial vaccines for healthy adults and provide long lasting immune suppressive responses. Therefore one or two doses are sufficient for life time of protection against pathogens and the disease it causes. But live attenuated vaccines have some limitations due to the presence of living microorganisms. It can cause problems in peoples who have weakened immune systems, long term health problems and who have had an organ transplant. Also live vaccines should be kept cool. That is another limitation of the live vaccines. Live vaccines are used to protect against yellow fever, chickenpox, smallpox, Rotavirus and measles, mumps, rubella (MMR combined vaccine).
Toxoid vaccines are inactivated toxins which are made by a pathogen that cause relevant disease and they do not cause disease. Compared to inactivate and live attenuated vaccines, toxoid vaccines do not consist of relevant microorganisms as live or inactivated. In the method of toxoid vaccines, immune responses are targeted to the toxins instead of the whole pathogen. These types of vaccines are used to protect against diphtheria, tetanus.
In Sub unit vaccines, a part of the microorganism is used to trigger immune responses instead of introducing inactivated microorganisms into the immune system. A good example for the subunit vaccine is the hepatitis B vaccine. This vaccine is produced by protein substances on the surface of the virus. The human papillomavirus vaccine is another example for the subunit vaccine. It is made from the capsid protein of the virus. Since these vaccines are using only specific pieces of the pathogen, they give very strong immune responses that are targeted to key parts of the pathogen .The advantage of the subunit vaccines is it can be used on almost everyone who needs them, including people with weak immune systems and long term health problems. But people may need booster shots to get ongoing protection against protection against diseases.

The latest step of the vaccine is the development of innovative vaccines and scientists are still working to create new types of vaccines. Recombinant vector vaccines and DNA vaccines are examples for the innovative vaccines.
DNA vaccines are consisting of viral or bacterial DNA and when vaccinated they will enter into human or animal cells. Then some cells of the immune system attack the cells which contain entered DNA. Because these cells live longer, the pathogen that produces these proteins naturally enters the body at a later time and is immediately attacked by the immune system. One of the advantages of these DNA vaccines is that they are very easy to manufacture and store. These vaccines are still in the experimental stage.
When considering the method of recombinant vector vaccines, it develops the immunization against diseases with a highly complex infection process by combining the physical properties of one microorganism with the DNA of another microorganism.

Different strategies for producing a vaccine.

Figure 1: Different strategies for producing a vaccine.

By considering all above here, we can understand that microorganisms' helps to heal and prevent most of the diseases made by microorganisms.

References:
https://www.vaccines.gov/basics/types
https://vk.ovg.ox.ac.uk/vk/types-of-vaccine
Image courtesy:
Featured image:
https://microbiologysociety.org/static/a7e1d65b-63e4-4ff4-849f49fd119d7421/600x400_highestperformance_/MMR-vaccine.jpg
Figure 1:
https://www.genscript.com/recombinant-vaccine.html

Microbe but not microscopic!!!

Microorganisms are usually organisms that are less than 1mm in size which include viruses, bacteria, fungi, protozoa and many microscopic algae. Microorganisms can be both harmful as well as beneficial to mankind. Bacteria are unicellular organisms that are capable of multiplying rapidly under suitable conditions. Bacterial cell represents the typical prokaryotic cell which have definite shape and ranges from typically between 0.5 – 5.0 micrometers in length.

But, there is someone who is exceptional…

Sulfur Pearl of Namibia, is the largest bacteria that was discovered so far. As some group of American, German and Spanish scientists discovered them in the coasts of Namibia which is thought to have linked with sulphur and nitrogen cycles of the environmental cycles. It was named as Thiomargarita namibiensis. The bacteria is found in chains of ten or more cells and each cell is spherical and 0.75mm in length which makes it visible to the naked eye. The chain of cells is enclosed within a slime sheath which makes them non motile.

As the name suggests, the bacteria feeds on sulphur found near the coasts and it gives a pearl appearance which makes it more visible. The shiny pearl appearance is due to the light reflected by the sulphur granules stored within the bacteria. The bacteria have been adapted to survive in an environment where there is low oxygen but high concentration of hydrogen sulphide which is considered to be toxic to most forms of life.

Micrscopical examination discovered that a large part of the volume of the cell is taken up by a vacuole. These organisms utilizes the vacuole to store the nitrates that it uses to oxidize sulfide. Thiomargarita survives in large numbers and is unstable in sea floor. When a storm emerges, it churns the water which provides a nitrate-rich water into the sediments. This is taken up by the bacteria and is stored inside the vacuole which enables them to survive for months.

Image of Thiomargarita bacteria which is about the same size as the head of a fruit fly.

Figure 1 : Image of Thiomargarita bacteria which is about the same size as the head of a fruit fly.

The analysts noticed that nitrate fixations inside the cell could be up to 10.000 times higher than in the encompassing ocean water. This mix of the oxidation of sulfide with the decrease of nitrate provides the microbes with an energy source which isn’t available for most microorganisms without oxygen. This makes it possible to utilize the bacteria to remediate coastal waters which are polluted by excess nitrates from agricultural run-off.

Reference
Heide N Schulz-Vogt (2002). Thiomargarita namibiensis: Giant microbe holding its breath. ASM news,volume 68, number 3, 2002.

https://www.eurekalert.org/pub_releases/1999-04/M-TLBS-160499.php
https://www.umsl.edu/microbes/files/pdfs/agiantmicrobe.pdf
https://www.eurekalert.org/pub_releases/1999-04/AAft-BBEF-160499.php

Image courtesy
Featured image : https://sciencepolicyivh.wordpress.com/tag/t-namibiensis
Figure 1 : https://www.abc.net.au/science/articles/1999/04/16/22180.htm

It’s time to protect yourselves from Rabies!!!

Rabies, one of the most dangerous diseases caused by animal bites. There are so many myths as well as unknown and unclear facts regarding this disease. Somehow this article is aimed to clear out many facts about rabies and provide better knowledge about this disease to the public.
Rabies is derived from the Latin word “rabere” which gives you the mean madness. This is one of the oldest human diseases, with the highest case fatality rate. Many controlling strategies have come out with time. Louis Pasture in 1881 worked on controlling rabies by immunization of dogs. In 1885 a vaccine for human rabies developed. In 1903 Adelchi Negri discovered Negri bodies, a major milestone achieved in the diagnosis journey of rabies.

Schematic diagram of the Rabies virus structure.

Figure 1: Schematic diagram of the Rabies virus structure.

Many people think just only about a furious dog when they hear the word rabies. But the story is totally different. Actually, rabies is a virus where it can transmit via the saliva of many mammals that live around us. So it is nice to know about this virus. Rabies virus comes under the family Rhabdoviridae. This is an enveloped bullet-shaped virus. Enveloped means this virus has a covering around this virus. But many of the enveloped viruses are very weak in harsh conditions. So we can have an idea about the survival condition of this virus once you know rabies as an enveloped virus. So would like to mention that this virus cannot withstand sunlight, along with exposure to air drying, boiling, or strong acids and alkalis. Also, this virus can be killed by iodine and detergents. Something very important to know about the rabies virus is that this virus does not invade the blood and cause disease. This is a neurotropic virus which means these viral particles are very like to nerves in our body.

Actually, there are seven types of this virus that differ from each other by small factors. But important to know is only the rabies virus type 1 which is the classical human rabies pathogen. This is a zoonotic infection. Which means they are transmitted from animals. There is a myth among people that rabies can transmit from human to human. There is no human to human transmission. But the virus present in human saliva. There are also extremely rare cases of mother to child transmission. Actually as mentioned above rabies only transmit from animals. What is important to know is this virus can infect warm blooded animals.

How does it transmit?

Transmission mainly occurs via a bite from an infected animal through broken skin. Scratches from paws contaminated with saliva, lick on an open wound also can cause entry of this virus to the body. Other routes of infection are intact mucous membranes such as the eyes, nose, and mouth.
There is evidence of getting rabies in non-bite exposures as well. Can it cause infection by inhalation? Yes, but there are only a few cases of getting rabies by inhaling large amounts of aerosolized virus. There are some evidence of getting rabies during surgeries such as corneal transplants and renal transplants. Ingestion of raw meat from animals with rabies is not a confirmed source of infection.

Something about epidemiology…

Rabies has become a burden to the world because about 55,000 people die from rabies each year.
Also, it has been found that though all age groups are susceptible, rabies is most common in children younger than 15 years. In contrast to other countries bats account for most human rabies cases in the United States.

Story of infection…

Actually, viral particles are present in secretions (eg: saliva, tears, urine, and milk) of an infected animal. The Rabies virus can enter into your body

  • via deep penetrating wounds due to the animal bite,
  • via abrasions and scratches on the skin,
  • via mucus membrane exposed to saliva from the licks.

But the virus does not penetrate intact skin.

Once the virus enters the body it replicates initially at the site of entry. Then it attaches directly to nerve endings. Then virus travels along the nerves towards the spinal cord and then to the brain. Not only that, these viral particles replicate massively within the central nervous system (brain and spinal cord).
Then these replicated viral particles spread centrifugally from the central nervous system to peripheral nerves. This spread is more via nerves to highly innervated tissues like salivary glands. Something very important for you to know is that the incubation period varies and it depends on three factors.

  1. Site of entry, If the entry wound is at the face, neck, or the head the incubation period is short. But if the site of entry is distal then the incubation period is long.
  2. Age of patient, children have a short incubation period.
  3. Amount of virus in the wound.

Features of rabid animals

rabies is primarily a zoonotic disease of warm-blooded animals. Actually, there are two major types of animal behaviors as
1.Furious rabies
2.Dumb rabies

Furious rabid dogs are very aggressive and bite without provocation. Features of them are characteristic of “mad dog syndrome”. Their voice changes and they growls in a hoarse voice. One of the major features is excessive salivation. Finally, there is a paralytic stage which leads to coma and death. Dumb rabid dogs are silent. They do not show any excitatory or irritative stage. They always try to withdraw from being seen or disturbed. Most of the time animals with dumb rabies die about in 3 days. One important fact about these types of animals is that the virus can be present in saliva 3-4 days before the onset of symptoms and during the cause of the illness till death.

Furious rabid dog

Figure 2: Furious rabid dog

Dumb rabid dog

Figure 3: Dumb rabid dog

Features of rabies in human

The onset of rabies in humans is fairly quiet. Initially, there is a period with fever, malaise, headache, tiredness, sore throat, lack of appetite, myalgia, and photophobia.

Then the disease worsens to the stage of excitement where mood changes occur. In this stage, the sleep is greatly disturbed anxiousness and irritation are the main features. Patients get frightened when examined or disturbed. They suffer from paresthesia and pain at the site of a healed wound. There is another prominent feature that is the tone of the affected muscles increases and it becomes generalized with time. Man also shows two major types of feature during infection as animals. They are furious rabies or encephalitic type and paralytic or dumb rabies.

Furious rabies is the most common type among humans which accounts for about 80% of total cases. The autonomic nervous system is affected mainly in this type. These patients show excessive salivation, lacrimation, sweating, and blood pressure changes. They also suffer from laryngopharyngeal spasms which is commonly called as hydrophobia. This is a condition that provokes with the attempt to drink water, water splash on the skin, sight, or sound of water. So that the respiration gets occluded due to spasms. In Contrast to furious rabies, paralytic or dumb rabies affects the spinal cord of the human mainly

Something interesting about the laboratory diagnosis of rabies in animals 

Laboratories perform only postmortem diagnosis for animals. The animal is killed and the head is separated first. Then the head is transported in a leak-proof wide-mouthed container. Then it is put into a secondary container and ice is packed in-between them. If the animal is small whole carcass is sent to the laboratory.

There are only two places in Sri Lanka to do laboratory diagnosis. They are the Medical Research Institute (MRI) and Teaching Hospital Karapitiya.

If there is a delay in transportation brain is dissected by a veterinary surgeon.

Something interesting about the laboratory diagnosis of rabies in humans

There are antemortem as well as post-mortem diagnosis for humans. Ante-mortem samples like corneal impressions, nuchal biopsies, and saliva are taken from patients. Post-mortem samples are taken from the cut parts of the salivary gland and brain.

What happens after an exposure?

A rabies exposure is categorized mainly into two as Major exposure and Minor exposure. There are many factors to consider to determine whether the exposure is major or minor. They are mentioned in the rabies management guidelines and will be managed accordingly after considering the type of exposure. There are instances in which the incident is not considered as an exposure. They are mentioned in the following list as they are really important,

  1. Contamination of intact skin with the saliva of a proven rabid animal.
  2. Eating leftovers that were consumed by a rabid animal.
  3. Drinking raw milk of rabid cow or goat.
  4. House rat bites.
  5. Drinking water from a well where an animal has fallen and died.

Persons at high risk of exposure like lab staff, veterinarians, and animal handlers are given post-exposure therapy.

Things to do after an exposure…

At the place of accident ;

  • Wounds should be washed immediately with soap and water at least for 5 minutes.

At the hospital for further treatments;

  • Wounds should be cleaned thoroughly with 70% alcohol or Povidone-iodine.
  • Anti tetanus immunization should be inoculated when necessary.
  • Antimicrobials should be prescribed if necessary to control bacterial infection.
  • Wound dressing could be done to prevent bacterial infection.
  • If suturing is indicated, it should be done after infiltration of the wound/s with RIG.

Rabies vaccine

Figure 4: Rabies vaccine

The situation of rabies in Sri Lanka in a nutshell

In Sri Lanka, transmission of rabies takes place mainly via the domestic cycle. Averagely 20 human deaths per year were reported in Sri Lanka in last years. Many important rabies preventive activities are currently working on society in order to minimize this condition. Vaccination of dogs, habitat control by removal of garbage sites, and continuous monitoring and evaluation are prominent among them.

References 

Greenwood, D., Slack, R. C., Barer, M. R., & Irving, W. L. (2012). Medical Microbiology E-Book: A Guide to Microbial Infections: Pathogenesis, Immunity, Laboratory Diagnosis and Control. With STUDENT CONSULT Online Access. Elsevier Health Sciences pp.596-601

Image courtesy :

Featured image:- https://images.app.goo.gl/Q4tKJC7K8NFzdv3Z6

Figure 1 :- https://images.app.goo.gl/As6eaFrPUAcvQ3vZ6

Figure 2:- https://images.app.goo.gl/BrwzNE79qyGjEjJM6

Figure3:- – https://cf.ltkcdn.net/dogs/images/orig/204182-2120×1414-tiredolddog.jpg

Figure 4:- https://images.app.goo.gl/HYqrvNrnSDDCihLRA

Healthy life with friendly microbes

With the name of “microbes”, very first things that come into our mind are “food spoilages, harmful, disease causing, dangerous and hazardous”. But not all the microbes are that kind. Many microbes are beneficial. Some are used in industrial purposes; some are used in food making, enzyme production, antibiotic production, and there are some microbes that live within the human digestive system which are beneficial to our body; called “probiotics”.
The term “probiotics” was first used by Lilly and Stillwell in 1965, to describe beneficial microorganisms and different substances produced by them that stimulate the growth of another, as the opposite of “antibiotics”.
Probiotics are living microbes that beneficially affect the host animal by improving its intestinal microbial balance and help to maintain a healthy gut. This is done by different substances that are produced by microorganisms. Lactobacilli, Bifidobacteria, Lactococci bacterial species (Lactic acid bacteria) and yeast are some microbes that are commonly used as probiotics.
Normally we get probiotics into our body with food that we take, like yogurt, cheese etc. These probiotics generate a symbiotic association with the human digestive system that the human digestive system provides a surface for colonizing probiotics, and probiotics provide many different kinds of benefits to the human body.

Foods containing probiotics

Figure 1: Foods containing probiotics

Probiotics adherence to the intestinal epithelial cell lining and act as a shield to protect receptor sites from pathogenic bacteria, enterotoxinogenic pathogens. Binding of probiotic bacteria to the intestinal tract surface is providing a protection from pathogenic bacterial cells. Probiotics has the ability to stabilize the intestinal microflora.
Probiotics produce different substances that are beneficial to human body functions. Some lactic acid bacteria produce substances that increase the content of vitamin B complex in fermented foods. Some probiotics have the ability to improve the digestibility or absolute amounts of some dietary nutrients in diets. Some lactic acid bacteria are used as a treatment for lactose intolerance in humans. Lactose intolerance is a medical condition that is difficult to digest lactose within the digestive system due to low levels of the β galactosidase enzyme ( lactase enzyme), resulting in bloating, flatulence and abdominal pains. Lactase enzymes produced by probiotics like Lactobacilli have the ability to break down lactose into glucose and galactose and make a relief for lactose intolerance.

Probiotics in milk

Figure 2: Probiotics in milk

Lactobacillus GG is the most studied probiotic organism in human digestive system and it has proven that Lactobacillus GG has the ability to decrease the toxin level produced by Clostridium difficile and control diarrhea cause by Clostridium difficile.
Enzymes produced by probiotics play a major role in the human digestive system. Enzymatic hydrolysis has been shown to enhance the bioavailability of proteins and fat in diets that we have taken. Bacterial proteases produced by probiotic bacteria have the ability to increase the production of free amino acids and this production is beneficial when the host has a deficiency in endogenous protease production.
Most of the time, the first allergic reaction in humans may be the allergic reactions in milk fed infants due to inability to digest milk proteins by casein enzyme. Probiotics like Lactobacillus GG and other Lactobacilli have the ability to degrade milk proteins into smaller peptides and amino acids and facilitate protein digestion in infants and prevent allergic reactions.
Researchers have proven that the probiotics have the ability to prevent alcohol induced liver damage and significant reduction in the incidence of colon tumors in the human body. Not only that, probiotics and their symbiotic associations are important in immune modulation, lowering serum cholesterol, lowering blood pressure, shortening rotavirus diarrhea, reduction of bladder cancer.
Now we can understand that probiotics play a major role within our body that helps to maintain body functions. But, it is not suitable to take probiotics by people with immune system problems, people who are critically ill and people who have had surgery.
We can get probiotics with dietary supplements and with food sources specially yogurts that provide Lactobacillus acidophilus, Lactobacillus casei, and food sources Kefir, some cheeses, miso, kombucha , pickles etc.
It is important to take enough probiotics with our meals to maintain a healthy gut since colonization of probiotics within the digestive system act as a protective army against harmful microorganisms and maintain good health condition within our body as a natural protective mechanism.


References:

Barry R. Goldin, (1998), “Health benefits of probiotics”, British Journal of Nutrition, 80, Suppl. 2, S203-S207

David R. Snydman, The Safety of Probiotics, https://academic.oup.com/cid/article/46/Supplement_2/S104/276784 by guest on 21 January 2021

S. Salminen et al., (1999), “Probiotics: how should they be defined? ”, Trends in Food Science & Technology 10 107-110

Image courtesy:

Featured image:
https://www.gutmicrobiotaforhealth.com/science-community-defends-effectiveness-of-probiotics/

Figure 1:
https://blog.mercy.com/probiotics-vs-prebiotics/

Figure 2:
https://www.saccosystem.com/cat-2/en/products-and-solutions-for-the-food-industry/26/probiotics-for-the-food-industry/124/

Battle between pressure and microorganisms in food industry

Microorganisms and pressure both have a huge everlasting relationship from the past time. In modern day, people are trying to seek more and more methods to overcome the problem which rose with the food security. In that process, pressure leads a main role with the showing many sub pathways to new methods of food preservation. Pressure dependent food processing methods are a more dominant way of food preservation in modern society .This article is mainly focused on the scientific background which lies on the pressure treated food. There is a high potential to produce high quality food by using the high hydrostatic pressure. That has a great impact on the microbiological safe and extended shelf-life of the food. Bacterial spores are a more dominant and resistant group which cannot be inactivated by pressure only. For low acid foods, combination treatments which use both high heat and pressure have been proposed as a method of preservation. Viruses and their infectivity can be abolished without destroying their ability to elicit antibodies.

high pressure treated sausages

Figure 1-high pressure treated sausages

The idea of using high pressure in food preservation is not a new thing to the world. In 1899, Hite was reported as the first person who used it as a food preservation method. He reported that milk can be kept sweet for longer with a pressure treatment. Hite and his group (1914) also reported the preservation ability of high pressure on the fruits too. But it was not successful with the vegetables as fruits. He thought that fruits and fruit based juices responded well to the high pressure because yeasts and other organisms having most to do with decomposition are very susceptible for the high pressure. But with the spore forming bacteria these methods were gone in different uncontrollable pathways.
Now let’s move into the real scientific things happening to the microorganisms with the pressure. This mainly affects the biological and chemical changes of the microorganism cell. The cell wall is less affected by high pressure than the membrane. Generally, no morphological changes can be observed in prokaryotes and lower eukaryotes by observation under a light microscope due to pressure gradient. In case of the volume capacity, high pressure treatments favours biochemical reactions that leads to volume decrease while it can retard reactions which leads to expansion of cell volume. Studies carried out on volume changes in proteins have shown that the main targets of the pressure are hydrophobic interactions which stabilizes the α-helical and β-pleated sheet forms of protein, and is not significantly influenced by pressure. That means enzymes have a little bit of capability to withstand high pressure. With that case, auto lysing fruits and vegetables do not respond much more with the high-pressure treatments. A high-pressure treatment may not always deal with complete inactivation of microbial activity. They may inure a proportion of the population. Again, the recovery of the injured cells will depend on the conditions after treatment. Compounds such as salt (sodium chloride) added to the plating media which can act as a selective agent and drop the regeneration of injured cells.

dealing with high pressure techniques in oyster production

Figure 2- dealing with high pressure techniques in oyster production

When we are dealing with the endospores, we have to do a different type of pressure based preservation method. Bacterial endospores can be extremely resistant to high pressure. They can survive under physical treatments such as irradiation and heat as well. They can tolerate the pressure treatments above the 1000Mpa too. Applying two different pressure levels in different stages is the most suitable method to overcome this problem. In first pressure treatment would germinate the spores while second one leads to destruction of germinated spores. This process could be done repeated several times and that leads to new technique called pressure cycling. Nucleic acids are relatively can tolerate high pressure and with the hydrogen bonds, it is more stable with the high pressure. However, the enzyme mediated steps Pressure treated fruit jams and sauces became first commercially available product in japan. With the treatment of jam in 400 MPa for up to 5 min at room temperature, a new product was established. It showed a significant reduction in microbe count. That showed the path for many more high pressurized food types to the market. Pressure treated orange and grapefruit juices were available in France in early 1994.

Pressure treatment in vegetables was a great problem because it is very sensitive to high pH and provides space for more pathogenic spore producing bacteria. However the most successful pressure treated food in the USA was guacamole. The taste between the pressurized ones and heat treated ones has a significant difference and more people adhere to the pressure treated guacamole. Sliced cooked ham and other meat products in flexible pouches can be successfully treated with the high pressure methods. The shelf life of the ham can be kept for 60days with this technique under chilling storage. High pressure treatment is the final step after the packaging process. That guarantees an addition safe from pathogenic microbes to food. Another successful event of pressure based preservation is production of oyster based food. The initial aim of this method regarding oysters is eliminating Vibrio spp. from the food. But some strains can be survived under high pressure also. But reduction of the amount of pathogens made this a better method. With the year by year, new products were introduced to the market. Complete meal kits have recently been launched in the USA with the help of pressure treatment. It is more likely that the range of added –value, high quality pressure treated food will rapidly expand within the next few years.

meal kit production under the pressure

Figure 3- meal kit production under the pressure

References –
Microbiology of pressure-treated foods M.F. Patterson
Department of Agriculture and Rural Development, Northern Ireland and Queen’s University, Belfast, UK
2004/0950: received 16 August 2004, revised and accepted 10 December 2004
https://sfamjournals.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2672.2005.02564

Image courtesy;
Featured image-
https://www.digitaltrends.com/home/what-is-a-pressure-cooker/
Figure 1-
https://courses.lumenlearning.com/boundless-microbiology/chapter/physical-antimicrobial-control/
Figure 2-
https://www.ift.org/news-and-publications/food-technology-magazine/issues/2016/may/columns/processing-oysters-high-pressure-processing
Figure3-
https://www.packworld.com/home/blog/13371942/high-pressure-processing-and-packaging-continues-to-grow

Microbial Spoilage of Meat and Human Lifestyle

Humans are one of the carnivore animals in the animal kingdom. They are frequently searching for nutrition to survive their life on the earth. Protein is the main energy compound in the human body. Then their main protein resources are meat and fish. Meat is shown to play a huge role for the human protein uptake. Indigenous people were used to hunting for their proteins during the prehistoric era. Humans had farmed animals before the industrial revolution. They fulfilled their protein necessary from farmed animals’ meat. They are interested in food security because of surplus meat products. They need methods to protect their surplus meat. They had learnt that microbial and physical actions can be caused to spoil meat. After harvesting meat, they need proper methods to keep their protein deposits. Meat has high nutritional value and it may be attacked by microorganisms easily. These causes are resulting in reduction in the quality of the meat product and its nutritional value too.
Microbial spoilage of meat occurs quickly as compared to other food products. Approximately 25% of world’s food produced post-harvest of post slaughter is lost to microbial degradation of food alone. Meat is an ideal culture medium for many organisms because it is high in moisture, rich in nitrogenous content and various degrees of complexity and plentiful of minerals and accessory growth factors. The breakdown of fat, carbohydrates, protein of meat impart off odors, off flavors and slime formation. Most spoilage microorganisms come externally to contaminate. Then there are two types of microorganisms according to their infections, such as some are accessed through infection of the living animals (endogenous). Examples are Anthrax, brucellosis caused agents, others are accessed by contamination of the meat post-mortem (exogenous). Bacteremia and sources and nature of external contaminants are main causes for exogenous spoilage. Meat is the first-choice animal protein for humans and consumption of meat is continuously increasing worldwide. The annual per capita consumption increased by 2.6 folded in 2000 and will increase by 3.7 folded by 2030 compared to that of the 1960s. On the other hand, the rich nutrient matrix meat is subject to various types of spoilage depending on handling and storage conditions.
There is an equilibrium between invasion of the tissues and removal of the invading organisms such that the tissues of healthy animals are normally free from bacteria. Meat can be contaminated by bacteria that persists on powered tools (air-driven knives) used in carcass dressing. External contamination of the meat is a containing possibility from the moment of bleeding until consumption. In the abattoir itself there are a large number of potential sources of infection by microorganisms, such as air-borne contamination, instruments used in dressing (hooks, knives, saws), aqueous sources and soil adhering etc.
Some meat spoilage microorganisms may be shown specific characters and they are symptoms too. Bacteria in aerobic conditions are shown slime on meat surplus, discoloration, colonies and off odors. Yeats are shown yeast slime, discoloration, off-odors and tastes, fat decompositions. Molds are presented with surface stickiness and whiskers, discoloration, odors and fat decomposition. Bacteria in anaerobic conditions are shown gas production and sourcing.

Figure 01

Figure 01

There are some factors affecting the meat spoilage such as temperature, moisture, pH, oxidation-reduction potential, atmosphere and high pressure. The most important single factor governing microbial growth is temperature. The higher the temperature the greater is the rate of growth. Many meat microorganisms will grow to some extent at all temperatures from below 0̊ C to above 65̊ C, but for a given organism, vigorous growth occurs in a more limited temperature range. Spoilage organisms in three categories. Psychrophiles (-2̊ C and 7̊ C), Mesophiles (10-40̊ C) and Thermophiles (43-66̊ C). After temperature the availability of moisture is perhaps the most important requirement for microbial growth on meat, although some types of bacteria may remain dormant for lengthy periods at low moisture levels, and spores resist destruction by dry heat more than by moist heat. The availability of moisture is complementary to that of osmotic pressure, which is a function of the concentration of soluble, dialyzable substances (salts, carbohydrates) in the aqueous medium. High solute concentrations tend to inhibit growth. Molds and yeasts tolerate higher osmotic pressures than bacteria.
pH of meat will be determined by the amount of lactic acid produced from glycogen during anaerobic glycolysis and this will be curtailed if glycogen is depleted by fatigue, inanition or fear in the animal before slaughter. Most bacteria grow optimally at above pH 7, and not well below pH 4 or above pH 9. Immediately after death, whilst temperature and pH are still high, it would be expected that the dangers of proliferation of and spoilage by anaerobes would be great. That such does not generally occur appears to be due to the level of the oxidation-reduction potential which usually does not fall for some time. A major grouping of microorganisms can be made on the basis of the oxygen tension which they need or can be made to tolerate aerobes, anaerobe and facultative. The exposed surfaces of fresh meat at chill temperatures would normally support the growth of aerobes such as members of the genera Pseudomonas. The degree of pressure inactivation is affected by the type of microorganisms, the pressure applied, the duration and temperature of the applied process and pH of the medium. The inactivation of microorganisms by high pressure appears to be due to intracellular damage. There is considerable variation in susceptibility to pressure between the types of microorganism found in meat.
There are prophylaxis methods to prevent spoilage of meat such hygiene, biological control, antibiotics and ionizing radiation. For controlling enzymatic, oxidative and microbial spoilage, low temperature storage and chemical techniques are the most common in the industry today. It is essential to store the meat at lower than 4°C immediately after slaughtering and during transport and storage as it is critical for meat hygiene, safety, shelf life, appearance and eating quality. Although, microbial and enzymatic spoilage can be stopped or minimized at lower temperature. However, oxidative spoilage cannot be prevented by freezing. A combination of chemical additives such as Tertiary Butyl Hydroxy Quinine (TBHQ) and ascorbic acid can be most effective for controlling spoilage of meat and meat products.

Figure 02

Figure 02

References:
Iulietto, M., Sechi, P., Borgogni, E. and Cenci-Goga, B., 2015. Meat Spoilage: A Critical Review of a Neglected Alteration Due to Ropy Slime Producing Bacteria. Italian Journal of Animal Science, 14(3), p.4011.

GILL, C., 1983. Meat Spoilage and Evaluation of the Potential Storage Life of Fresh Meat. Journal of Food Protection, 46(5), pp.444-452.

Mutwakil, 2011. Meat Spoilage Mechanisms and Preservation Techniques: A Critical Review. American Journal of Agricultural and Biological Sciences, 6(4), pp.486-510.

Image courtesy:
Featured image:
https://www.pinterest.com/pin/415175659392992163/

Figure 01
https://www.istockphoto.com/photos/rotten-meat

Figure 02
https://lovefoodhatewaste.co.nz/fridge-freezer-technologies/

Poisonous mushrooms

Approximately 14,000 different mushroom species have been discovered by mycologists around the world. They are divided into several different genera. Many edible and inedible species are found in each genus, and many of them look similar. Only a few of the 70-80 poisonous mushroom species are potentially lethal when consumed. Toxins known as illudins are found in poisonous mushrooms and cause gastrointestinal symptoms. It is safe to touch the mushroom. To damage you, the unsafe toxins in mushrooms must be eaten. Inhaling mushroom spores does not usually result in death. Since mushroom spores are everywhere, everybody is constantly inhaling them. These spores can cause allergies in sensitive people.
Mistaking a mushroom for another has serious implications. As a result, it’s crucial that they are correctly identified. We can use a mushroom guide to identify them. Pictures of poisonous mushrooms in the guide are useful. The odor of poisonous mushrooms is typically unpleasant and acrid. A few distinguishing features can assist you in determining whether or not it is poisonous. And those traits are not found in edible species. They are a positive sign that you can leave the mushroom alone if you recognize them. White-gilled mushrooms are often harmful. Those with a ring or annulus around the stalk, as well as those with a sack-like base (bulging section) at the bottom of the stem known as a volva, are also poisonous. Rings are commonly wrapped around the stem just below the cap. The volva is mostly found underground. The existence of a volva, particularly one with a ring around it, is generally an indication of a poisonous species. Red-stemmed or red-capped mushrooms are either poisonous or highly hallucinogenic. Amanita muscaria is the most well-known red-colored mushroom. The fungus Podostroma cornu-damae is a rare Asian species. Trichothecene mycotoxins are found in its red fruiting bodies, which can cause multiple organ failure.

Figure 1

Figure 1

Never consume a mushroom unless you are absolutely sure it is safe to eat. The destroying angels (Amanita species) are white mushrooms. These extremely toxic fungi match with edible button and meadow mushrooms in appearance. The Amanita species, especially death cap mushrooms (Amanita phalloides), are the most common dangerous mushrooms. It is to account for the majority of human deaths caused by mushroom consumption. It looks a lot like those edible mushrooms. Heat-stable amatoxins are found in the death cap mushroom and the lethal dapperling (Lepiota brunneoincarnata) mushrooms. Accidental ingestion of deadly dapperling causes serious liver toxicity, which can be fatal if treatment is not received immediately.
Conocybe filaris contains the same mycotoxins as the death cap mushroom, and eating it can be deadly. And also Webcaps (Cortinarius species) and Autumn Skullcap (Galerina marginata) are lethal. In addition, certain mushrooms, such as those belonging to the genus Psilocybe, may cause hallucinations and other brain effects, but none of these are thought to be long-term.
Poisoning symptoms include stomach pain, violent abdominal pain, peeling skin, low blood pressure, liver necrosis, vomiting, and bloody diarrhea, which cause rapid loss of fluid from the tissues and extreme thirst, as well as acute kidney failure and death if left untreated.

References:
Menser, G. P. (1977) Hallucinogenic and poisonous mushroom: Field guide RONIN Publishing, Inc., Oakland.
https://www.planetdeadly.com/nature/poisonous-mushrooms
https://www.britannica.com/list/7-of-the-worlds-most-poisonous-mushrooms
https://www.betterhealth.vic.gov.au/health/healthyliving/fungi-poisoning

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https://naturalsociety.com/wp-content/uploads/Mushrooms_Poisonous_mushrooms_Amanita_735-350-2.jpg

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Oil spills and microbes

Oil spills are a major problem in present times which occur mainly in marine environments. The leaks of oil pipes which have built under the ocean break open or the leaks from ships create a catastrophic environmental pollution in marine ecosystems. There is no foolproof way to remove oil from the open ocean. These oil spills are extremely harmful as the chemicals made up of are toxic. So they create a heap of troubles. Mainly those oil spills float on top of the water and thus the animals who inhabit the sea surface such as birds, filter feeders and otters are more vulnerable. Those can coat the animal’s feathers and fur, leaving them unable to fly or swim. Eventually the oil gets sink and affects the rest of the marine life below it. The small and large fish can consume the oil droplets and they could have cancer like diseases. Thus by consumption of fish and seafood, humans also could have sicknesses by accumulating petroleum oil in the bodies. This destroys the ecosystem balance and food chains that exist within it. However not only the oil spill damages the ecosystem, but also the cleanup mechanisms do even more damage. If the chemical cleanup is done, it requires more chemicals to be put into the oil and break it up and make it easier to remove. So then the amount of chemicals seeping into the ocean is doubled at the end.
Therefore, as a solution for that, scientists have proposed a bioremediation method. Using bacteria for cleaning up oil. They have discovered a rod shaped bacteria that consume oil for energy. Bioremediation is an important process that uses decomposers and green plants or their enzymes to improve the condition of polluted or contaminated environments. To remove the oil spills, Alcanivorax bacteria and Methylocella silvestris can be used. Alcanivorax borkumensis is an alkane degrading marine bacteria which naturally propagates and becomes predominant in crude-oil-containing seawater when nitrogen and phosphorus nutrients are supplemented. Methylocella silvestris is a bacteria of rod shape. These microbes help to clean the oil spills and recover the marine environments.

Figure 01

Figure 01

It was the deep water horizon oil spill into the Gulf of Mexico in 2010 that instigated the scientists to seek refuge in bioremediation. It involved leakage of over 4.2 million barrels of oil that endangered many of the marine species and ecosystems extending from tidal marshes to the floor of the deep sea. The conventional methods like mechanical cleaning, use of chemicals to burn spoiled petroleum to overcome it. This causes lots of damage to the environment. So the scientists pay their attention to bioremediation techniques

Figure 02

Figure 02

Reference:
https://www.downtoearth.org.in/news/natural-disasters/microbes-to-fight-oil-spillage-in-oceans-indian-scientists-devise-new-technology-73828

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Featured image:
https://en.m.wikipedia.org/wiki/Oil_spill#/media/File%3AOiled_Bird_Black_Sea_Oil_Spill_111207.jpg
Figure 01:
https://commons.m.wikimedia.org/wiki/File:Oil_spill_in_San_Francisco_bay.jpg#mw-jump-to-license
Figure 02:
https://scienceofhealthy.com/bioremediation-of-oil-spills/

The nanotechnology in water microbiology

Microbiology is the study of microscopic organisms which are invisible to the naked eye. Some of them are bacteria, viruses, fungi, archaea and protozoa. In water microbiology mainly consider microbes used in water purification, remediation and treatment. The nano scales are very tiny and measured by nanometers(10−9 m). Nanotechnology used to research and build innovations on the scale of atoms and molecules.

The lotus effect is a very interesting natural example for the nano effect. The lotus leaves show ultra hydrophobic effect due to nanoscopic architecture on the surface which decreases the adhesion nature of water to the leaf surface.

The World Health Organization (WHO) shows that around 1.40 billion people in the world do not have access to safe drinking water and also there are about 9300 deaths per day due to waterborne diseases in 2016. Many pathogens are antibiotic resistant and so it’s very hard to remove them from contaminated water. So efficient pathogen detection methods are needed to detect them easily and quickly. There are various methods used in waste water purification. The current water purification methods are trickling filters, rotating biological contactors which are used in biofilms. And also there is activated sludge method and water treatments with sedimentation, filtration and chlorination. The current sewage and industrial waste water purification methods are effective. But nanotechnology facilitates the process and increases efficiency of the process. The bioactive nanoparticles act as more effective alternatives for chlorine. So here we talk about a few nanotechnological uses in water microbiology.

Nanomembranes increase efficiency of waste water filtration through thin layered materials which are allowed to pass water through it while trapping salts, bacteria, viruses and metals in the membrane.

nanomembrane used in wastewater treatment

Figure 1- nanomembrane used in wastewater treatment

And also the high microbial loads at biofilms can form foul in normal water filters and it may decrease the quality of drinking water. Nanotechnology is the better solution for the biofouling. There are nano biocides like metal nanoparticles and nanomaterials have been successfully used with nanofibres. Actually the nano biocides are like bacteriocins which decrease bacterial density, but here used nanotechnological nanomaterials, not chemicals or other methods. Such nano biocides show good antimicrobial activity, efficient purification and it keeps water stability.

In water nanomicrobiology the highly specific and highly adsorption surfaces which can be used in water purification and remediation. They are carbon based surfaces (CNTs) and metal based surfaces (FeO, TiO2, Ag, Al). These surfaces are made by nanotechnology which can remove inorganic, organic contaminants and bacteria in wastewater. As an example the monodispersed nanosilver bioconjugate particles are produced by mycelium of fungi, Rhizopus oryzae. It shows high antimicrobial activity. Such specific methods can be influenced by the drastic decrease of microbial population like E. coli and other coliform bacterias. And also the nano-Ag on polymeric membranes can enhance the oxidation process and can decrease the unpleasant smells (biofouling).

Nanocatalysts are also used to increase the catalytic activity in water treatment. Because such nanocatalysts have higher surface area and its properties depend on shape. It increases the degradation of contaminants. For example the semiconductor materials are used as the catalytic nanoparticles.

These all nanomaterials are innovated, produced and demonstrated in laboratories according to the safety standards before releasing. The long term risk assessment of engineered nanoparticles (ENPs) is very important while applying nanotechnology to freshwater, wastewater or groundwater purification or treatment. These nanomaterials can be re-used or recycled to reduce the cost. Nanotechnology can improve handling water contaminations and purification. Nanotechnology based approaches are more easier, efficient than bulk methods, time consuming, durable, eco friendly and very interesting.

Nano-Ag in water treatment

Figure 2- Nano-Ag in water treatment

Nano-single wall CNTs

Figure 3 – Nano-single wall CNTs

References:
https://www.researchgate.net › 2878…Web results (PDF) Nanotechnology in waste water treatment … – ResearchGate
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7148861/

Image Courtesy:
Featured image:
https://www.properla.co.uk/lotus-effect/
Figure 1:
https://www.azonano.com/amp/article.aspx?ArticleID=3170
Figure 2:
https://link.springer.com/chapter/10.1007/978-3-030-17061-5_17
Figure 3:
https://www.azonano.com/amp/article.aspx?ArticleID=983

MICROPLASTICS- DANGEROUS THAN EVER IMAGINED?

Plastic particles less than 5mm are called microplastics. Microplastics are added to the household drainage from personal care products such as toothpaste, cosmetics, clothing micro fibres etc. It is estimated that around 2 million microplastic particles can be discharged into an average wastewater treatment plant from 400,000 houses just in a day. So, the amount of microplastics added to the environment is enormous. Man made products incorporated into natural ecosystems always cause novel consequences. When the products are ultra-fine particles, it is really challenging for the scientists to discover the changes occurring in the atmosphere by the addition of those particles. Effects caused by the addition of an enormous amount of ultra-fine microplastic to the environment are not fully discovered. But Interaction of these microparticles with microorganisms are recently studied and some unwilling, negative consequences are being revealed by several scientists.
Jake Bowley and colleagues have described some criteria about how antimicrobial resistance of bacteria is increased by forming interactions with microplastics made of polyethylene and polypropylene. Microplastics easily resemble the structure and size of the naturally occurring components that bacteria would adhere with. Since, the naturally occurring particles are not rich in the wastewater, proliferation of pathogenic bacteria in the wastewater was balanced with wastewater treatments. But the proliferation of these pathogenic bacteria is rapidly increased because of the microplastics. Unfortunately, most of the water treatment plants have no process of removing the microplastics. So, they are being received by the natural waterways when the treated water is released.
Bacteria in the wastewater accidentally attach with the microplastics and secrete polysaccharides which form a slimy layer (biofilm) on the microplastic. Because of this layer formation, more bacteria will be attracted to the microplastics. Bacteria in the biofilm gain 30 times greater resistance to antibiotics than the original free bacteria. Wastewater has an enormous number of pathogenic bacteria. So that Proliferation rate and resistance of pathogenic bacteria will increase in the presence of microplastics in the wastewater. This will cause adverse effects in the environment in many ways.
Biodiversity in the Waterways will be affected with the highly increased number of pathogens. Fish and other edible species in the water ways might get infected with these pathogens. By consuming the affected water or fish, the pathogens will reach the digestive tract of humans. These pathogenic bacteria would replace the place of microorganisms which help the cells of the digestive tract. This will affect the function of the digestive tract and eventually will cause human health issues.

Circulation of microplastic in the environment.

Figure.1 Circulation of microplastic in the environment.

Interaction of pathogenic microorganisms with microplastics will enable the long distant transport of the pathogens while acting as a vector in water. Also, will pose longer retention time with the increasing antimicrobial resistant and impacting food webs. Even with very few studies made on this crisis scientists have found many harmful effects of microplastics. Still there are more to discover the interactions of microplastics. Some of the studies say that microorganisms can degrade the microplastics which will lead in a positive impact on the environment. But this would not wipe away all the microplastics in the environment in a considerable brief period. Because the released microparticles into the environment are enormous. So, it is our responsibility to reduce the use of plastics and replace it with environmentally friendly, Bio degradative materials.

References:
Dung NgocPhamLeroneClarkMengyanLi Microplastics as hubs enriching antibiotic-resistant bacteria and pathogens in municipal activated sludge. Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, NJ 07102, United State
https://blogs.biomedcentral.com/bugbitten/2021/03/05/microplastics-and-microbes-have-we-created-a-new-disease-vector/
https://www.sciencedaily.com/releases/2021/03/210319183936.htm
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You are mainly microbe!

We are so concerned about the cleanliness of our bodies. But did you know that after all cleansing processes with soap, shampoo and hand sanitizer we are mostly microbes. The human body is made up with about 10 trillion cells. But we are holding 100 trillion microbes on and inside our body. This is called the human microbiome. Because of their small size, however, microbiomes make up only about 1-3% of the body’s mass.

But we are not born with all of these microbes. There is a sterile environment in the mother’s womb but we get our first bacteria before we are even born. When the baby passes through the vaginal cavity they ingest certain bacteria from the mother’s microbiome. Furthermore lots of microbes are introduced for a new born baby with breast milk as well as from other people who are closely in contact with the baby. As we cuddle, kiss and play in the dirt eventually thousands of species of bacteria will enter our body making it one of the most complex ecosystems in the world.

These microbes inhabit all parts of our body that are exposed to the environment, such as the mouth, skin, vagina, airways and gut. Normally, when people think of microorganisms in the body, they think of pathogens. Because of that reason researches were focused on harmful bacteria for a long time and human friendly, beneficial bacteria were ignored. Although the first experiment on the microbiome was conducted as early as the 1680s by the scientist “Antonie von Leewenhoek”, who found striking differences between his own fecal and oral microbial population.

Without the trillions of microbes we share our body with, we would struggle to break down essential nutrients in our intestines. Also these microbes help to regulate our immune system, protect against other bacteria that cause disease, and produce vitamins including B3, B6, B12, riboflavin and thiamine, and Vitamin K, which is needed for blood coagulation. Our immune system acts between states of aggression and tolerance. To balance these two status, help of the microbiome is truly needed. The microbiome teaches the immune system which cells to fight and which cells to leave alone. With the absence of these bacteria, our body overreacts on all kinds of cellular material we pick up resulting in asthma and allergies.

Microbes living on our skin produce chemicals which have the ability to prevent transient pathogens from colonizing the skin or they stimulate the skin’s immune system to fight against pathogens. Some skin bacteria prefer to live in warm, dark places on the body, reacting to skin oils and sweat, producing chemicals which give a particular aroma to the human body.
The food we eat has an effect on our gut microbiome based on the ability of microbes to use energy from food. The consumption of high-fat products reduces the total volume of the intestinal microbiome population and induces the growth of bacteria that support a fast fat deposition. Also the gut microbiome tells us when to eat. The bacteria living in our stomach, named Helicobacter pylori, tells us when we are hungry or full. Therefore any damage to the natural gut microbiome is identified as a cause for obesity.

Figure 1

Figure 1

Considering all these beneficial facts, it is very important to protect our microbiome for a healthy life. The biggest threat to the microbiome was and still is the widespread use of antibiotics. Antibiotics do not recognize the difference between the good and the bad bacteria. Although antibiotics have saved many lives, some people are using them without any precaution or as prophylaxis. To protect and improve your microbiome avoids the use of antibiotics and other antimicrobials. And make sure to eat a balanced diet with vegetables, fermented foods and probiotic products. Most importantly play in the dirt a little more often and ensure that you have a happy and healthy microbiome.

References:
https://www.mymicrobiome.info/10-facts-about-the-microbiome.html
https://depts.washington.edu/ceeh/downloads/FF_Microbiome.pdf
Image courtesy:
Featured image:
https://rhapsodyinwords.com/2017/01/23/what-you-need-to-know-about-the-most-influential-organ-in-your-body/
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https://rootedforlife.wordpress.com/tag/let-your-children-play/

Clinical Microbial Identification by MALDI-TOF Mass Spectrometry

  • Introduction
    MALDI-TOF (Matrix-assisted laser desorption/ionization time-of-flight) is a powerful analytical mass spectrometry technique that has been successfully introduced in clinical laboratories initially as an identification tool about ten years ago. Since then, MALDI-TOF has been widely used in routine laboratory practice due to its rapid (in about 2 min) and accurate identification of pathogens, especially for the identification of microorganisms for medical diagnosis.
  • MALDI-TOF MS overview
    MS is used to detect the m/z ratio and MALDI-TOF MS provides a rapid, accurate and sensitive spectra of the bio-analytes within a sample. MALDI is an ionization technique in which a matrix absorbs energy from ultraviolet lasers to create ions from large molecules with minimal fragmentation. The m/z ratio can be determined by the TOF of the ions which the detector measures TOF of ions to calculate masses of ions.

In the above methodology, the sample is co-crystallized with the matrix on the sample target and to be desorbed and ionized by the MALDI ion source (e.g. ultraviolet laser). The ion molecules, including the microbial peptides/proteins, are accelerated by the electric field into the TOF analyzer. All the ions are separated by TOF in accordance with the m/z ratio and a mass spectrum.

The α-Cyano-4-hydroxycinnamic acid (HCCA) and 2,5-dihydroxybenzoic acid are MALDI matrices used for various microbial analysis. For microorganism identification, positively charged peptides/proteins with a molecular weight between 2000 and 20,000 m/z are used. The sequence and size of ribosomal proteins are highly conserved among different bacterial species, and therefore be used to identify individual types of bacteria. Individual mass peaks are used for microorganism identification and provide valuable information for the fingerprinting of bacteria. To enable rapid, accurate, easy and reliable microorganism identification, the new MS system was designed with a highly automatic operational workflow and analysis process.

  • Principles of MALDI-TOF
    Maldi is a soft ionization technique used in mass spectrometry, allowing the analysis of biomolecules such as DNA, proteins, peptides & sugar or polymers such as dendrimers and macromolecules. It is a three steps method.
    The sample is mixed with a suitable matrix & applied to a metal plate.
    A pulsed laser irradiates a sample triggering desorption of matrix material.
    Ionization of analyte molecules
  • Every minute counts to a life
    Bruker‘s MALDI Sepsityper enables identification of gram negative bacteria, gram-positive bacteria and yeast from positive blood cultures within 30 minutes.
    Hence, this is a rapid method to Investigate Bacteremia and Septicemia. MALDI Sepsityper Septicemias enables faster results, which physicians can act upon to manage bloodstream infections, engage in the fight against resistance, and improve patient outcomes.
  • What are the advantages of MALDI-TOF MS?
    The use of MALDI-TOF MS in the medical lab reduces the time between specimen collection and diagnosis. Also, pre-examination processing of organisms for analysis by MALDI-TOF MS is technically simple and reproducible. Another benefit of this technology is accuracy.

The improved performance of MALDI-TOF MS over traditional methods seems to have contributed to an increase in the reporting of some relatively rare species. For example, reporting of skin and peri-prosthetic joint infections due to Staphylococcus lugdunensis, a member of the coagulase- negative staphylococci, appears to have increased due to the use of MALDI-TOF MS. This has also been the case of urinary tract infections caused by Aerococcus urinae and other rare uropathogens. Aerococcus urinae is a catalase negative, Gram-positive cocci that often forms pairs, chains, or triads and looks similar to streptococci not only on gram stain but also when grown on blood-agar. Further, biochemical methods are frequently unable to discriminate Aerococcus species from each other or other Gram-positive bacteria. Given the difficulty in accurately identifying A. urinae and the fact that it is a relatively uncommon cause of urinary tract infections, it is not surprising that urinary tract infections caused by A. urinae appear to have been under-reported prior to the use of MALDI-TOF MS.

The speed with which MALDI-TOF MS can identify microorganisms helps to quickly guide treatment decisions, which is especially critical when the infecting pathogen is unexpected. Identification of anaerobes and yeast provide additional examples of the benefits of MALDI-TOF MS in terms of improving the turnaround time. Anaerobic organisms typically have slow doubling times. They are also not very biochemically active and often require a large amount of biomass for definitive identification using biochemical methods. Thus, the length of time it takes to get to a final identification using traditional methods is largely spent on growing the organism, not on performing analytical testing. This can delay the time to diagnosis significantly. For yeasts, faster identification can significantly improve clinical outcomes.

  • Limitations
    For organisms commonly encountered in the clinical laboratory, MALDI-TOF MS can accurately identify most closely related species. However, there are some exceptions. The inability to discriminate between related species can be due to the inherent similarity of the organisms themselves. For inherently similar organisms, it is common to report to the group, complex or genus level. In cases where differentiation to the species level is clinically necessary, supplemental testing should be performed.

In conclusion, the introduction of MALDI-TOF MS into the clinical laboratory has brought more timely and accurate identification of microorganisms with subsequent improvement in diagnosis and reduction in the time to appropriate therapy. As these platforms continue to improve and become more widely available, the practice of clinical microbiology will be transformed.

References:
Ying Li, Mingzhu Shan, Zuobin Zhu, Xuhua Mao, Mingju Yan, Ying Chen, Qiuju Zhu, Hongchun Li and Bing Gu (2019), Application of MALDI-TOF MS to rapid identification of anaerobic bacteria, BMC Infectious Diseases (https://bmcinfectdis.biomedcentral.com/articles/10.1186/s12879-019-4584-0) accessed date – 27th March, 2021

Fernando Cobo, (27th September,2013), Application of MALDI-TOF Mass Spectrometry in Clinical Virology, Open Virol J (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3821086/)
accessed date – 27th March, 2021

MALDI-TOF Advantages and Disadvantages, Published: 5th Sep 2017 in Health (https://www.ukessays.com/essays/health/malditof-advantages-disadvantages- 3265.php)
accessed date – 27th March, 2021

  • Image courtesy
    Featured image:
    MALDI-TOF MS methodology: Image is from the article of Current status of MALDI-TOF mass spectrometry in clinical microbiology from the Journal of Food and Drug Analysis, Volume 27, Issue 2, April 2019, Pages 404-414
    https://pubmed.ncbi.nlm.nih.gov/30987712/
    accessed date – 27th March, 2021

Contribution of Microbiology in Searching of Life beyond Earth

Imagination of life beyond earth is impossible for us as humans. The main reason is the lack of suitable conditions for human survival due to the presence of extreme environmental conditions in other planets as examined so far by scientists. Even in past studies on earth believed that in extreme environments life is not possible at all. The reason is living organisms tend to be sensitive to drastic environmental changes such as changes in temperature, pressure, drought, salinity, pH. The exceeding of optimum ranges causes disruption in crucial interactions of biomolecules which keep them folded and functional, occurs quickly destroying cellular integrity[1]. However recent studies have shown the prediction about extreme environments on earth was wrong. What’s this extreme environment? Is the environment where the environmental conditions are too low or above from the optimum that is resistant for the survival of biosphere (living organisms). Extreme environmental conditions are mainly in two types as physical and geochemical extremes. Physical extremes are physical conditions such as temperature, irradiation, pressure meanwhile geochemical extremes are such as pH, desiccation, salinity, redox potential. Humans and non extreme organisms evolved to a specific narrow range of environmental conditions. The invention of the ability of microorganisms to thrive in extreme environments expanded the range of habitats on earth by opening a new dimension of microbiology towards astrobiology. Astrobiology is a field of studying the origin of life, life in extraterrestrial habitats, disperse of life in the universe. The reason is that even the earth’s early life consisted of extreme conditions which are similar to that of environments found in outside planets such as Mars, Venus. According to the phylogenetic analysis the most ancestral species is believed to be an anaerobic hyperthermophile. Hydrothermal environments are considered as locals of origin of life since the environment provides energy, carbon sources, electron acceptors, and a variety of inorganic surfaces suitable for the formation of biopolymers. Hydrothermal environments are targets for the origins of life in other planets within the solar system and beyond.

Thermophilic bacteria

Figure 1: Thermophilic bacteria

The organisms in extreme environments are classified as thermophiles, hyperthermophiles, psychrophiles, acidophiles, alkaliphiles, halophiles, piezophiles. The significance of these organisms is not only they live in extremes but often they require extreme conditions for survival. Thermophiles are capable of living in the temperature range of 45°C – 80°C while hyperthermophiles tolerate the temperatures above 80°C. These kinds of species are found in geothermally heated areas on earth like deep sea hydrothermal vents. Acidophiles live in very lower pH ranges that grow optimally at pH values of 2.0 [3] This is an interesting feature as the acidity is caused as a result of metabolism of the organism and not a condition imposed by the system. Alkaliphiles are microorganisms that grow optimally at pH values above 9.0, often with pH optima around 10.0, while showing little or no growth at near neutral pH values [4]. Psychrophiles are microorganisms that grow at or below 0 optimum growth at 15 upper limit of 20 [2] variety of environments stratosphere to the deep sea. Halophiles are organisms that grow in elevated salt concentrations such as from 10% to saturated sodium chloride concentrations and even in salt crystals.[5] The environments where halophilic microorganisms are found include aquatic habitats of varying salinity, salt marshes, surface salt lakes, subterranean salt lakes, and some other places [6]. Piezophiles are microorganisms that have adapted to high-pressure environments and can grow more easily under high hydrostatic pressure conditions than at atmospheric pressure [7]. Piezophiles are widespread in the seafloor and deep within the Earth’s crust.

The unique metabolic and cellular adaptations are expressed in these types of organisms to fit with their unique habitats. The life external to the earth is searched via this same potential of microbes to tolerate extreme features as shock pressure, irradiation, high temperature variations etc. often experienced in ejection from one planet to find habitable areas of planets in the universe.

References:
Horikoshi, K.; Grant, W.D. Extremophiles: Microbial Life in Extreme Environments; Wiley-Liss: New York, NY, USA, 1998.
Rothschild, L. Extremophiles: Defining the envelope for the search for life in the universe. In Planetary Systems and the Origins of Life; Pudritz, R., Higgs, P., Stone, J., Eds.; Cambridge University Press: Cambridge, UK, 2007.

Morozkina, E.V.; Slutskaya, E.S.; Fedorova, T.V.; Tugay, T.I.; Golubeva, L.I.; Koroleva, O.V.
Extremophilic microorganisms: Biochemical adaptation and biotechnological application. Appl. Biochem. Microbiol. 2010, 46, 1-14.

Horikoshi, K. Alkaliphiles: Some applications of their products for biotechnology. Microbiol. Mol. Biol. Rev. 1999, 63, 735-750.

DasSarma, S.; Arora, P. Halophiles, Encyclopedia of Life Sciences; Nature Publishing Group: London, UK, 2002.

Litchfield, C.D.; Gillevet, P.M. Microbial diversity and complexity in hypersaline environments: A preliminary assessment. J. Ind. Microbiol. Biotechnol. 2002, 28, 48-55.

Abe, F.; Horikoshi, K. The biotechnological potential of piezophiles. Trends Biotechnol. 2001, 19, 102-108.

Image courtesy :
Featured image: :https://thermophilesyo.weebly.com/uploads/6/0/1/0/60108077/6116846_orig.jpg
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How Vitamin D-Rich Mushrooms Can Support Vascular Health

 

Mushrooms are cholesterol and fat free, which can help reduce your intake of saturated fat.

While fat is an essential part of a healthy, balanced diet, helping your body absorb fat-soluble vitamins that are essential for healthy brain and nerve function, too much is usually not a good thing. Unfortunately, many people still consume too much saturated fat. Mixing mushrooms into your meat dishes is a way to instantly reduce your intake because mushrooms are cholesterol and fat free. Researchers are examining the effects of Portobello and Shiitake mushrooms on preventing the development of high-fat diet-induced atherosclerosis.

Mushrooms rich in vitamin D contain selenium, which is needed to regulate your heart functions.

The trace element and antioxidant selenium is what your thyroid gland uses to function properly and to help regulate your heart and digestive system. Without it, your thyroid and heart would be adversely affected, which is why intake of selenium is important.
Selenium also helps protect your body from damage caused by oxidative stress. This oxidation often causes inflammation, which can increase the risk of heart disease. A series of 16 controlled studies analyzing 44,000 people with heart disease found that taking selenium supplements lowered levels of the inflammatory marker C-reactive protein (CRP).
Selenium is found in some meats such as pork and beef, as well as in fish. Adults need a minimum of 55 mcg of selenium per day, while pregnant or breastfeeding women may need more.
With about 8 mcg of selenium in three ounces (85 g) of white mushrooms, this serving provides 15% of your daily value (DV). Brown mushrooms have even higher levels of selenium per serving, packing 40% DV in just three ounces. So the next time you go shopping, slip into a container of heart-healthy mushrooms to help maintain proper heart function.

Fungi can play a role in preventing cardiovascular disease.

Several studies have examined the influence of mushroom consumption on certain metabolic markers like blood pressure and oxidative and inflammatory damage, which may reduce the risk of developing cardiovascular disease. Mushrooms can aid circulation by reducing plaque build-up and may be a contributing factor in reducing cardiovascular problems. They also contain potassium, which helps protect your blood vessels from oxidative damage, a major reason blood vessels can become inflamed and restrict flow.

 

References-
https://orangemushroom.net
https://www.mushroommatter.com
Image courtesy:

Featured image:
https://www.mushroomcouncil.com/wp-content/uploads/2017/12/nutrition-vitd-header-1440×500.jpg

Happy tummy, happy me

We are not at all alone in our bodies. Trillions of microorganisms are there with us inside and outside of our bodies. Have you ever wondered that the number of bacteria that accompany our bodies exceeds the number of our own cells?? Even though it may be hard to believe it was the truth, and if you have imagined that all these microorganisms and “BAD” for us, it is a complete misunderstanding. It is true that microorganisms can cause diseases, but there are some who are very important and beneficial for our health.
There are tons of research going on to find out the involvement of these microorganisms who live with us and their health benefits. Different organs in our bodies contain distinct groups of microorganisms, but the gut microorganisms, also referred to as gut microbiome has become the most attractive topic in today’s biomedical research. The reason for this attractiveness is their involvement in controlling certain diseases, such as obesity, heart disease, Type 2 diabetes and a wide range of other conditions.
An international study carried out by Francesco Asnicar, Sarah E. Berr and Nicola Segata (in 2021) have found that the composition of the gut microbiome is clearly influenced by the things we eat. That means by controlling our own diets, we get the chance to manipulate the gut microbiome to become healthier.
Further, they have found that diets rich with whole foods can support the growth of beneficial gut microbes that promote good health. But highly processed foods with added sugars, salt and other additives have totally the opposite effects and can worsen cardiovascular and other diseases.
Ultimately, the message they give to the world is just simple. It was almost the old or may be the most familiar diet advice to have more whole unprocessed foods and to reduce the consumption of processed foods. So, enjoy your healthy meals and make sure your microbial friends are happy!! REMEMBER they will definitely make you happy too!!

Figure 1

Figure 1

Additionally, if you want to make your tummy a better place for these beneficial bacteria some extra tips can be given for you. You can add more fermented food products such as cheese, yoghurts to our meals. These fermented foods contain nutrients preferred by these beneficial gut bacteria. Another helpful dietary advice is to include naturally fermented foods containing probiotics (live beneficial bacteria), such as sauerkraut, pickles, miso, certain types of yogurt to the diets. It is helpful for establishing a healthy gut flora in your tummy.


References

Microbiome connections with host metabolism and habitual diet from 1,098 deeply phenotyped individuals. Asnicar et al,2021.
https://www.nytimes.com/2021/01/11/well/eat/diet-gut-microbiome.html
https://www.todayonline.com/world/how-right-foods-may-lead-healthier-gut-and-better-health

Image courtesy

Featured image- https://www.health.harvard.edu/heart-health/gut-check-how-the-microbiome-may-mediate-heart-health
Figure 1- https://www.bradfordclinic.com.au/blog/gut-health-part-3

Food For Thought

Among all the amazing creations of Mother Nature, human body is an outstanding work of art that holds lots of mysteries yet to be discovered. Human body consists of nearly 15 trillion cells that are working together to keep us alive.
But are you aware that our body holds more microbial cells than our own human cells? Human body carries more than 100 trillion microbial cells including bacteria, fungi, archaea and viruses which add up about 1.5 kg to our total body weight. This collection of microorganisms inhabiting the human body is commonly known as the human microbiome.
Human microbiome plays a key role in the survival and well being of humans without us even knowing that. These microbes are shown to be essential for human development, immunity and nutrition. It helps in digesting our food, regulates our immune system, protects us from pathogenic bacteria and produces vitamins including B vitamins B12, thiamine and riboflavin and Vitamin K.
We acquire these healthy microbes through several mechanisms including from birth where the newborn gets microbes from mother’s birth canal, from breast milk which contains prebiotics and probiotics and from skin of mother and other caregivers and from the environment including other people, pets, plants, soil, water and food.

Influences and functions of human microbiome

Figure 1: Influences and functions of human microbiome

The majority of the human microbiome lives in our gut, particularly in the large intestine. The intestinal microbiota of newborns has low diversity and dominated by the phyla Proteobacteria and Actinobacteria and later becomes dominated by Firmicutes and Bacteroidetes. These microbes play a significant role in digestion of food, nutrient absorption and improving immunity against pathogens.

Functions of gut microbes in humans

Figure 2: Functions of gut microbes in humans

Here comes the most interesting part!
Do you believe that these gut microbes which reside far away from our brain have a great impact on our mental health and our behaviors? According to many researches including a study done by Timothy Dinan and his team in 2015, it has been seen that the formation of a complex gut microbiota in humans has played an important role in enabling brain development and has a great impact on cognitive function and fundamental behavior patterns, such as social interaction and stress management.
But how is that possible?
This is mainly due to the direct and indirect connections between gut and the brain which creates a gut-brain axis. Gut and brain are strongly connected through several pathways mainly through the neural pathway which includes vagus nerve and neuropod cells and the neuro-endocrine pathway which consists of brain chemicals and hormones. It has been seen that there are multiple bidirectional routes of communication between the brain and the gut microbiota through this gut-brain axis. These microbes can affect the functioning of the brain by producing neurotransmitters and neuromodulators as well as protect the brain from harmful effects of certain pathogens.

Methods of communication between brain and gut microbes

Figure 3: Methods of communication between brain and gut microbes

All these facts show us that it is crucial to maintain a healthy gut microbiome to ensure and improve our mental well being. So how can we do that? The easiest way is to eat good food. Eating a diverse range of food including plant based food such as beans, banana, almond, garlic, ginger, asparagus, etc. and especially fermented food such as yoghurt, cheese and kefir are shown to improve the gut microbiota. Consumption of prebiotics and probiotics also has profound effects on restoring healthy gut microbes and ensuring the better survival of beneficial gut microbes.
Prebiotics are compounds in food such as complex carbohydrates (oligosaccharides), glycosylated proteins and dietary fibers that induce the growth or activity of beneficial gut microorganisms. These compounds mostly act as food for healthy gut microbes and promote their growth. Prebiotics can be easily acquired by consuming plant based diets.
Probiotics are microbial dietary adjuvants that are made of beneficial, friendly lactic acid bacteria such as Lactobacillus and Bifidobacterium and yeasts such as Saccharomyces boulardii. They are formulated to reflect the composition of healthy gut microflora and have many health benefits for humans. They can be acquired as commercially available supplements or by consuming fermented food especially fermented milk products. Consumed probiotics adhere to intestinal cells and protect them against pathogenic bacteria by acting like a shield and masking receptor sites for pathogenic bacteria and enterotoxigenic compounds.Sample Text

Health benefits of probiotics

Figure 4: Health benefits of probiotics

There are other more advanced methods to restore the healthy gut microbiome such as fecal transplantation (FMT) as clinical therapies but they are still requiring further experimentation and acceptance by the general public.
So finally we can see that our gut microbes are real unsung heroes who have been with us from the very beginning of our lives and help us thrive and become healthy humans. So it is required to pay our gratitude towards them by taking good care of them in return.
If we can fix our diets to rejuvenate this natural gift presented to us, we will be able to restore our physical and mental well-being and improve our behaviors as well. Along with that it is essential to realize the importance of natural birth in introducing a healthy microbiome to infants and the role of breast feeding in establishing a healthy gut microbiota which will be a long term investment. All these will lead to create a more healthy community of people that are mentally fit and able to serve this world without any restrictions. Just think about that and remember to eat good food to have good thoughts!

Figure 5

Figure 5

References:
https://www.researchgate.net/publication/273402142_Collective_unconscious_How_gut_microbes_shape_human_behavior
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4991899/
https://www.nationalgeographic.com/science/article/how-many-cells-are-in-your-body#:~:text=Based%20on%20an%20adult%20man’s,a%20jar%20full%20of%20jellybeans.
https://www.micropia.nl/en/discover/stories/on-and-in-you/#:~:text=You%20and%20your%201.5%20kilos,kilograms%20of%20your%20body%20weight.
https://depts.washington.edu/ceeh/downloads/FF_Microbiome.pdf
https://www.nccih.nih.gov/health/probiotics-what-you-need-to-know#:~:text=Probiotics%20may%20contain%20a%20variety,yeasts%20such%20as%20Saccharomyces%20boulardii.
Image courtesy:
Featured image: https://bit.ly/3dbTEcp
Figure 1: https://bit.ly/2P3ok7X
Figure 2: https://bit.ly/39lJkNV
Figure 3: https://bit.ly/3d9vzmx
Figure 4: https://bit.ly/3lVFH6o
Figure 5: https://bit.ly/3u2DkBs

Fermented foods for long life

The idea of bacteria feeding on food might sound a little scary, but stick with us.From yogurt to soy sauce, go through a process called fermentation. During the fermentation process, these beneficial microbes break down sugars and starches into alcohols and acids.It’s no wonder that fermented foods have been growing in popularity over the years. More and more people have discovered their health benefits and how tasty they are too. Fermentation is a relatively efficient, low energy preservation process which increases the shelf life and decreases the need for refrigeration or other form of food preservation technology. It is therefore a highly appropriate technique for use in developing countries and remote areas where access to sophisticated equipment is limited. Fermented foods are popular throughout the world and in some regions make a significant contribution to the diet of millions of individuals.

There are thousands of different types of fermented foods, including: cultured milk and yoghurt, kimchi, sauerkraut, kombucha, shrubs, kefir, miso, natto, cheeses, tempeh.

Figure 01

Figure 01

A number of health benefits are associated with fermentation. In fact, fermented foods are often more nutritious than their unfermented form. It helps break down nutrients in food, making them easier to digest.Fermented foods can prevent bad bacteria from growing in your gut. You might say a yogurt a day keeps the bad gut bacteria away. Fermented foods like yogurt, kefir and sour pickles have lactic acid bacteria in them as a result of the fermentation process. Lactic acid bacteria are a type of good bacteria that lower the pH level of whatever environment it lives in, making it less hospitable for bad bacteria. Having a lower pH in your gut means that if and when you do consume sickness-causing bacteria, it won’t be as likely to make you ill. Fermented foods can prevent bad bacteria from attaching to your gut. Not only does lactic acid bacteria lower the pH of your gut to prevent bad bacteria from growing, it also prevents bad bacteria from attaching to the walls of your gastrointestinal tract. Lactic acid bacteria compete with bad bacteria. If it can’t attach to the walls of your gut, it gets passed through your digestive system and out of your body.

Figure 02

Figure 02

Fermented foods deliver more probiotics to your body. Probiotics can help your body in multiple ways: They help alleviate gastrointestinal symptoms, prevent viral infections, and decrease stress levels. Some fermented foods that include probiotics are yogurt, sauerkraut, kimchi, miso and kombucha. Probiotics are important in maintaining a balanced gut microbiota, the balance between good and bad bacteria, especially during periods of life when the balance is most fragile, which includes childhood and later years. Eating fermented foods can increase your energy, because the bacteria in your gut are allowing more vitamins and minerals to be absorbed and used by your body. Fermented foods can reduce brain fog, anxiety, moodiness and depression. Fermented foods may reduce the risk of developing colon cancer.
Curious to know where to go to stock your kitchen with these wonder foods? You can also try making your own fermented foods at home, as they have an incredibly long shelf.

References:

One Health, Fermented Foods, and Gut Microbiota, Bell et al., 2018.

https://onlinelibrary.wiley.com/doi/abs/10.1002/9781119237860.ch39

https://www.masterclass.com/articles/what-is-fermentation-learn-about-the-3-different-types-of-fermentation-and-6-tips-for-homemade-fermentation#how-does-fermentation-work

Image courtesy:

Featured image:
https://www.umassmed.edu/nutrition/blog/blog-posts/2019/6/fermented-foods-for-gut-health/

Figure 01:
http://mariechantalblog.com/2018/04/a-full-guide-to-fermented-foods/

Figure 02:
https://www.tasteofhome.com/article/the-health-benefits-of-fermentation/

Most important microbe of our time

After all this time since the dawn of genetics and biotechnology, out of the barely explored wilderness of a genome of ours we have only studied a very limited fraction of these 3.5 billion base pairs of DNA. Whereas there are only a handful of species whose biology were studied more thoroughly than ourselves. Among them one of the most crucial and most studied species in the whole wide world is a microbe namely the world famous Escherichia coli. Biologists all over the world have studied this organism intensely for about a century, and have made it their guide, an oracle that can speak for all of life to venture upon uncharted waters in molecular biology, occasionally leading them to grab their Nobel prizes. Let’s see why & how a tiny single-celled microbe built up this much of a reputation to be the “molecular biologist tool box”.
Through E. coli we can see history of life as well as the future as it is being the cornerstone of many key findings in biology and genetics. As it turns out, all life including bacteria share a similar foundation which could be revealed by studying E. coli. It led to the discoveries in the structure of many genes, their regulatory nature and their function. Also it was implemented as a model system to study cell division process, bacterial metabolism, biosynthesis of cell walls, chemotaxis as well as its involvement in unveiling the nature of DNA replication, understanding the basis of mutations and evolution was crucial in understanding many theories that we take for granted today in day-to-day studies and research.
Apart from basic research, with the advent of novel biotechnology techniques, E. coli was implemented as a tool to carry out various functions like generating plasmid vectors, gene knockouts, and biosensors to whole genome editing applications which eventually lead to the achievement of a genetically modified organism rendering E. coli to be a key tool in biotechnology.
If it is discussed as to why this rod shaped gram-negative bacillus has borne such great caliber, much of it has to do with its growth characteristics. E. coli can grow in a considerably fast rate in chemically defined cheap culture media without forming aggregates allowing industrial scalability. And its strikingly organized genome with insertion sequences, remnants of many phages, high transport capacity and the fact that a major portion of the genome is uncharacterized for specific molecular pathways had a crucial impact in applied research and development where its genome could be engineered to develop novel strains of the organism that contain important biotechnological characteristics. This followed by extensive knowledge in its transcriptome, proteome and metabolome, rendered E. coli to be one of the most important species in molecular biology & genetic engineering research.
With all the knowledge we have on this wonder microbe and with all the research that is currently being conducted on it, the possibilities are virtually limitless. As a platform for genetic engineering, with the wide range of strains and plasmids that are available, E. coli is being implemented as a toolbox to venture into cutting edge research which will yield novel & profound insights into other microorganisms to discover new microbiological phenomena that will lead the next big leap in molecular biology & biotechnology. This will ensure that Escherichia coli, the meritorious model organism that revolutionized the whole world of molecular biology in the 20th century will continue to do so in the 21st century and beyond.

References :

https://www.sciencedirect.com/topics/medicine-and-dentistry/escherichia-coli
https://www.intechopen.com/books/-i-escherichia-coli-i-recent-advances-on-physiology-pathogenesis-and-biotechnological-applications/-i-escherichia-coli-i-as-a-model-organism-and-its-application-in-biotechnology
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4373459/

book:
Microcosm: E. Coli and the New Science of Life – Carl Zimmer

Image Courtesy:
Featured image:
https://www.offset.com/photos/magnification-of-e-coli-escherichia-coli-bacteria-under-a-color-58000

Did you ever wonder how milk becomes cheese?

Most people know that cheese is made from milk. Usually most cheeses are made with cow’s milk. This is due in part to the wide availability of cow’s milk and the fact that it offers optimal amounts of fat and protein. Some examples of cow’s milk cheeses include Cheddar, Swiss and Gouda among many others. However, in some parts of the world, people get dairy products from goats, buffalo, and sheep. Even more obscure types of milk can be used to make regional specialty cheeses. For example, camel’s milk is the basis for the South African Caracane cheese. Other cheeses can be made from horse’s, reindeer’s or even yak’s milk.
So how does a bucket of milk become cheese? Cheese making occurs in three main stages. In the first stage, milk is transformed into solid curds and liquid whey through the coagulation of the milk protein casein. The coagulation of casein is usually accomplished through two complementary methods, acidification and proteolysis. Acidification occurs when lactic acid bacteria ferment the disaccharide lactose, to produce lactic acid. Originally, cheesemakers relied upon naturally occurring lactic acid bacteria in the milk, but today, the process is usually standardized by the addition of domesticated bacterial ‘starter’ cultures, including strains of Lactococcus lactis, Streptococcus thermophilus and Lactobacillus sp. The production of acid by these bacteria causes casein to slowly coagulate. This process is often assisted by the addition of the enzyme chymosin, the active ingredient in rennet. Chymosin is an enzyme that is naturally produced in the stomachs of calves and other mammals to help them digest milk. Rennet is traditionally made from an extract of the intestinal lining of a milk-fed calf, which produces the protease chymosin to aid in the digestion of milk. But today cheesemakers get rennet from bacteria and yeast that have been genetically taught to make the enzyme. Chymosin removes a negatively charged portion of casein, resulting in the rapid aggregation of casein proteins.
In the second stage of cheese making, cheesemakers separate the curds, containing the casein and milk fat, from the whey. Depending on the type of cheese, the curds can be heated, salted, pressed, and eventually formed into wheels of various shapes and sizes. Cheese can be eaten fresh at this point, or the wheels can be left to age in a damp, cool place.
It is during the aging stage of cheese making that cheese is truly transformed from fresh cheese into the myriad flavors, aromas, and textures of mature cheese. As a normal part of the aging process, starter cultures and non-starter lactic acid bacteria continue to grow and metabolize the interior of the cheese, while the surface of a cheese is colonized by bacteria and fungi that form a multispecies biofilm, termed the ‘rind’ of the cheese.
The way a cheese looks, smells and tastes depends on many factors, including the animal that produced the milk, what the animal was fed, which bacteria were used in the starter culture and how the cheese was processed. Mozzarella cheese has a stringy quality because it’s kneaded like dough before being formed into its final shape.

Mozzarella cheese

Figure 1: Mozzarella cheese

The holes in Swiss cheese result from the growth of the bacterium Propionibacterium freundenreichii. The P. freundenreichii ferments the lactic acid present after the growth of the lactic acid bacteria. The products of this fermentation include propionic acid, which is one of the characteristic flavors of Swiss cheese, and CO2. Because P. freundenreichii prefers anaerobic conditions, growth occurs inside the wheel of cheese, and the CO2 produced during fermentation is trapped and forms the typical bubbles or holes found in Swiss cheese.

Swiss cheese

Figure 2: Swiss cheese

A related fungus, Penicillium roqueforti, is the key microbe in blue cheese. It can also be inoculated into milk destined to become blue cheese. Because P. roqueforti is a microaerophile, it prefers to grow in crevices created by puncturing a cheese with metal spikes after the wheels are formed. The P. roqueforti produces lipases that convert the fats in cheese to peppery free fatty acids and the methyl ketone 2-heptanone, which gives the characteristic blue aroma. The blue pigment seen in blue cheese is produced by P. roqueforti during sporulation.
It’s not a coincidence that some cheese smells funky. Washed rind cheeses, such as Epoisses and Limburger, are regularly washed with a brine solution during the aging process. This creates a moist, salty environment on the surface of the cheese in which certain species of fungi and bacteria thrive. One of the best-known species is the actinomycete bacteria Brevibacterium linens. The B. linens contribute to the reddish-orange color typical of these cheeses through the production of carotenoid pigments. Additionally, B. linens metabolize the casein proteins to a variety of volatile compounds, including amines and sulfur compounds, giving these cheeses their funky, sweaty aromas. The related bacterium B. epidermidis can be found growing on human skin and, not surprisingly, is thought to contribute to body odor. Some people don’t mind the smell. But if Mom or Dad brings home a block of Limburger, be prepared to hold your nose. So eventually you will understand actually the wonder is between different kinds of microorganisms which have the ability to produce different kinds of metabolic compounds and have specific activities that will result in various types of cheeses you enjoy today.

Blue cheese

Figure 3: Blue cheese

References:
https://www.washingtonpost.com/lifestyle/kidspost/ever-wondered-how-milk-becomes-cheese/2015/05/15/32abad22-ece8-11e4-8abc-d6aa3bad79dd_story.html
https://sclydeweaver.com/blog/how-is-cheese-made/
https://www.sciencelearn.org.nz/resources/827-the-science-of-cheese

Image courtesy:

Featured image:
https://recipes.howstuffworks.com/dairy/different-types-of-cheese.htm
Figure 1:
https://cheesemaking.com/products/30-minute-mozzarella-recipe
Figure 2:
https://blogs.scientificamerican.com/roots-of-unity/the-serendipity-of-swiss-cheese/
Figure 3:
https://www.healthline.com/nutrition/is-blue-cheese-mold

What is Dandruff?

Dandruff is not a disease but an unpleasant phenomenon. It’s a common scalp disorder affecting almost half of the population at the post-pubertal age and of any gender and ethnicity. It is characterized by flaking or scaling of the skin of the scalp which causes itchiness and shedding of white powder over the shoulders causing a very unpleasant look which also creates a negative self-esteem in both sexes. It is termed as seborrhoeic dermatitis. Earlier scientists considered Malassezia furfur as the causal agent of dandruff but latest studies show that two other forms of the fungus called Malassezia restricta and M. globosa are the causal organisms of dandruff.

A microscopic image of human dandruff

Figure 1 : A microscopic image of human dandruff

Dandruff is caused by an overgrowth of a fungus called Malassezia. It is a yeast-like fungus that grows on the scalp. Malassezia grows on everyone’s scalps naturally. So it is not a problem. But when only it penetrates deeper through the scalp’s natural barrier, it begins to cause problems by making the scalp itchy and can cause flaking. Malassezia globosa metabolizes triglycerides present in sebum resulting in the production of oleic acid as a lipid byproduct. During dandruff condition, the level of Malassezia increases by 1.5- 2 times its normal level. Oleic acid penetrates the top layer of epidermis, the stratum corneum and induces an inflammatory response in susceptible people which causes erratic cleavage of stratum corneum cells. Dandruff scale is a cluster of corneocytes which have retained a large degree of cohesion with one another and detach as such from the surface of the stratum corneum. The size and abundance of scales are heterogeneous from one site to another and over time. Parakeratotic cells often make up a part of dandruff. Their numbers depend on the severity of the clinical manifestation. This fungus is not contagious. So this disorder is not spread through contact of infected people to non-infected people.

Malassezia yeasts at the surface of the stratum corneum.

Figure 2 : Malassezia yeasts at the surface of the stratum corneum.

When this condition prevails for a long time, many other problems can also occur as follows.
· Acne: Contact of dandruff with the face may induce pimples. So dandruff is responsible for the sudden outbreak of pimples. A facial wash containing Salicylic Acid can be used to cleanse the face and prevent acne formation due to dandruff fallouts.
· Hair loss: One of the symptoms of dandruff is scratching of the scalp which is caused due to itchiness and extreme dryness. Prolonged scratching may cause damage to hair strands and their follicles and these results in hair strand breaking and falling off. In order to reduce the dryness of the scalp, aloe vera gel or coconut oil can be applied on the scalp as both of them have antifungal and antibacterial properties. And also anti-dandruff shampoo can be used to cleanse the scalp.
Several other non-microbial factors are also affected for excessive dandruff formation such as genetic and environmental factors. Excessive exposure to sunlight is known to cause exfoliation of the scalp. Over shampooing, frequent combing, use of certain cosmetic products, dusts and dirt are also affected for excessive dandruff formation.
The following treatments can be followed to minimize adverse effects caused by excessive dandruff condition. Antifungal treatments including ketoconazole, zinc pyrithione and selenium disulfide have been found to be effective against dandruff. Several plant extracts such as lemon, aloevera, fenugreek, henna and amla showed a good activity against dandruff because these extracts consist of antifungal compounds and could be safely used for dandruff treatments. Personal hygiene can be maintained properly by washing hair every two days once with mild shampoo. Combs, pillow covers and towels can be washed regularly. Avoid using others’ comb and towel. Oil hair 1 hour before hair wash. Avoid going out with oily hair. Use suitable herbal shampoo and conditioner. Avoid experimenting with new hair care products.
These treatments will guide for a better look and confidence by saying goodbye to dandruff. So everyone can try out and follow these good health habits to get rid of this awful and discomforting dandruff condition.

References:
Anupam Dikshit et al. (2012). “Botanicals for the management of dandruff. Medicinal plants”
C. Pie´rard-Franchimont, E. Xhauflaire-Uhoda and G. E. Pie´rard “Revisiting dandruff- Review Article”, International Journal of Cosmetic Science (13 March 2006)
Mamatha Pingili et al. “Antifungal activity of plant extracts against dandruff causing organism Malassezia furfur”, International Journal of bioassays (October 28, 2016)
S.Ranganathan, T.Mukhopadhyay “Dandruff: The most commercially exploited skin disease”, Indian journal of dermatology, 2010- ncbi.nlm.nih.gov.


Image courtesy:

Featured image:
https://images.app.goo.gl/rmq1w96z8vvGshiz9
Figure 1:
https://en.m.wikipedia.org/wiki/Dandruff
Figure 2:
C. Pie´rard-Franchimont, E. Xhauflaire-Uhoda and G. E. Pie´rard “Revisiting dandruff- Review Article”, International Journal of Cosmetic Science (13 March 2006)

Challenges Sri Lanka faces in using microbes in industries

Microbes, or microscopic organisms are widely used in large-scale industrial processes for thousands of years. They are crucial for the production of a variety of metabolites, such as ethanol, butanol, lactic acid, and riboflavin, as well as the transformation of chemicals that help to reduce environmental pollution. It is proposed that the widespread utilization of selected beneficial microbial biodiversity could revolutionize agriculture to a low-cost, eco-friendly and sustainable activity. However, there are big challenges Sri Lanka faces in using these microbes in industries. Some of the challenges are analyzed throughout this essay.
In the agricultural industry, one of the most troubleshooting problems is large-scale crops being attacked by several pathogenic microorganisms which lead to severe diseases to the plants. The European countries have overcome pest’s damages by using “microorganisms” as biocontrol agents but, in Sri Lanka, farmers or agricultural officers do not have the technology and research knowledge to pest control using microbes. Therefore, issues relating to pest controls still remain. If Sri Lanka uses these microorganisms’ intended technology, it can enhance the quality as well as the final crop yield of “Tea”, as it is one of the main export crops to the international market from Sri Lanka. However, the huge usage of the microorganisms without control would lead to the appearance of new species. This disrupts the balance of the natural ecosystem and pesticides would bio accumulate in food chains. If the microorganisms are controlled well, this method would be the best in pest control and disease control of crop plants in a country like Sri Lanka.
There are also deficiencies when it comes to the use of microbes in the medical and pharmaceutical industries in Sri Lanka. For instance, Sri Lanka is struggling to not only produce its own vaccines let alone have the facility to store them. Currently, Sri Lanka is administering the AstraZeneca “covishield” vaccine which can be stored at regular temperature and is only 62-90% effective, however, Pfizer and Moderna are 95% effective but it has to be stored at a temperature of -70 degree Celsius which is a facility Sri Lanka cannot afford. Besides, if there are enough provisions to extract and micro analyze the genomes of many pathogenic and spoilage bacteria, it may open new possibilities for the design of novel antibiotics which target essential functions of problematic bacteria. This shows a large amount of funding is not more directed to industrial biotechnology in Sri Lanka.
If you take the rubber industry, Microbes including E. coli naturally make small amounts of isoprene as part of their metabolism, but not nearly enough to be used on an industrial scale. Companies in the USA have found changes in metabolic pathways that converge to create an isoprene precursor by adding to the E. coli, a plant gene coding for isoprene synthase, an enzyme that converts the precursor directly into isoprene. They have ramped up microbial production of isoprene to such a scale that it can compete with petroleum-derived rubber. Sri Lanka being the world’s 6th largest exporter and the 8th largest natural rubber producing country does not have enough funds nor an organized system to start up biotechnological companies and utilize the added advantage it possesses. This is a major drawback for the rubber industry in Sri Lanka.
Compost is a widely accepted organic fertilizer in Sri Lanka and It is being produced using a wide variety of source materials at household to commercial scale. Producing good-quality compost safe for human health and the environment at large has become a challenge that should be addressed at various levels: from production to policy making. There are several challenges to be addressed to overcome the negative impact on the environment and public health. One major aspect affecting is the inadequate sorting/segregation of Municipal Solid Waste used for compost production. Municipal Solid Waste and poultry manure/litter, which are some common raw materials used in medium- to large-scale composting facilities in Sri Lanka, contribute to the spread of some pollutants of emerging concerns. Antimicrobial resistance determinants, micro-and nano plastics, and organic pollutants are major emerging pollutants that have not yet received the attention of policymakers and regulatory bodies in Sri Lanka.
The present study has focused on the isolation and identification of bacteria from hot water springs which have the potential of producing industrially important extracellular enzymes. Water and soil samples were collected from seven hot water springs located in Mahaoya, Wahava, Madunagala, Kivlegama, Gomarankadavala, Kanniya, NelumWeva in the country. At the same time, In Sri Lanka’s rural areas, freshwater supply heavily relies on single household dug wells in which have identified the presence of cyanobacteria cells as well as potent cyanotoxins at levels alarmingly higher than the World Health Organization (WHO) guidelines. It is concerning that the toxins have been detected throughout the year in the dug wells, which can result in chronic illnesses. The water chemistry and microbiome of household wells in Medawachchiya, an area with a high prevalence of chronic kidney disease of unknown origin (CKDu) has been found. This could be the result of the high usage of microbes in industries.
Microbes are described as the main organisms able to carry out fermentation. Through indigenous fermentation, many products have been standardized and commercialized (ales, natural yeast; cheeses, natural fungi; wines, natural yeast), whilst many other products are made and commercialized in limited quantities for specialized markers or even remain uncommercialized. Some of the microorganisms of interest recently described for industrial fermentations require ‘extreme conditions’ for growth like high salt concentration or highly acidic pH. This is the case of halophilic or acid thermophilic microbes, respectively. Operating under these conditions causes corrosion (which affects the half-life of most of the bioreactor currently available), thus negatively affecting the implementation of these microorganisms at a large scale.
Another type of challenge is the competition with chemical catalysts. Industrial biotechnology has not developed as fast as expected due to some challenges including the emergence of alternative energy sources, especially shale gas, natural gas hydrate (or gas hydrate), and sand oil. The weaknesses of microbial or enzymatic processes compared with chemical processing also make industrial biotech products less competitive with the chemical ones. For example, the replacement of petrol with biogas. Bioprocessing is still not as effective as chemical processing, resulting in high cost of bio-products and the chemical industry is also evolving competitively in various ways including environmental friendliness, the use of renewable resources (biomass) for making chemicals that are normally derived from petrochemicals.
In the food industry, for instance, in Sri Lanka, there are many dairy farms and milk factories. However, cheese is a product that is still in demand. Cheese requires both microbes (lactic acid bacteria) and milk as its primary ingredients. Unfortunately, there is a scarcity of fresh milk for cheese production. So even if microbes are easily available in this instance, the deficiency of other raw materials makes this process an unfinished business. Agriculture raw materials for bioprocessing are becoming increasingly costly. There are about only three local cheese producers in Sri Lanka, while a large quantity is imported to the country. There is immense economic potential in cheese making and apart from being a good income earner, as a cottage industry, it could generate employment with more and more small dairy farms too. Since local production itself is a challenge, exporting becomes secondary.
In conclusion, it is evident that there are several deficiencies in the current Sri Lankan industries when it comes to the use of microbes. Lack of technology and funding has posed to be the biggest hurdle to overcome. Sri Lanka as a country is no less capable than the other countries that have progressed in utilizing microbes for the greater good. By overcoming the difficulties, Sri Lanka is guaranteed to prevail in its growth and experience what it truly is about.

References
https://scielo.isciii.es/scielo.php?script=sci_arttext&pid=S1139-67092004000200001
https://microbialcellfactories.biomedcentral.com/articles/10.1186/1475-2859-11-111

Image courtesy
Featured image:
https://www.reference.com/science/harmful-effects-microorganisms-6f2cc6b780a6bf67

Bioremediation of plastic waste and its importance

Bioremediation is a branch of biotechnology that use living organisms like bacteria, fungi or their enzymes for the removal of contaminants, toxins, heavy metals or other pollutants from the environment. Bioremediation is possible due to the ability of microbes to utilize a wide range of organic substances as a carbon source. Microbes are often able to convert harmful substances to harmless or less harmful chemicals through metabolic pathways. They can also immobilize toxins and heavy metals.
Plastics are a wide range of synthetic materials that are of great use to humans. Plastics are present in many human consumables from toys, tools, automobiles, packaging, furniture, and a lot more. Metal, glass, wood, and leather that was used historically had now been replaced by plastics. Many properties make plastics invaluable, such as; being lightweight, hygienic, flexible, waterproof, and highly durable. Durability is a key feature for the value of plastic items, but is also a huge problem to the environment. Plastics are made from fossil fuel based petrochemicals like natural gas or petroleum. These are large polymers and not easily decomposed in nature. It is estimated that a single use plastic bottle takes 450 years to fully decompose which is equivalent to 5 human generations. Since humans use a wide range of plastic goods where production surpass decomposition, plastic waste is responsible for the pollution of water, soil, as well as the air we breathe. The normal decomposition of plastics also impose a problem due to the formation of microplastics which will be discussed in this article.
Microplastics are all types of plastics less than 5 mm in length. The decomposition of discarded plastics or synthesis of microplastics for use in consumables such as soap, shampoo, and toothpaste releases microplastics to the environment. The problem with microplastics is the bioaccumulation within animal and plant tissue by ingestion. Due to the small size, microplastics cannot be physically extracted from polluted sites. Some commonly used methods of plastic disposal are landfills, incineration, recycling, road construction, and petrol production. However, methods like landfills result in soil and underground water pollution, incineration can release toxic gases and microplastics to the atmosphere, recycling and petrol production require a high investment of capital for startup and continuation. Bioremediation appears to be the best solution for the present plastic waste.
Even though plastics are resistant to microbial attacks certain species of bacteria and fungi can be utilized for its degradation. According to scientific literature, biodegradation of plastic involve four stages; adherence of microbes to the surface of polymer, exploitation of polymer as a food source, primary degradation of polymer, and ultimate degradation of polymer. Under aerobic conditions biodegradation of plastics produce CO2, H2O, and biomass, anaerobic conditions additionally generate CH4. Some of the fungi that can be utilized for plastic decomposition are Aspergillus niger, Penicillium funiculosum, Paecilomyces variotii, Aspergillus terreus, Aspergillus sydowii and Gliocladium virens. Bacteria capable of degrading plastics had been isolated from areas that are already polluted with plastics such as mangrove soil, landfills, and marine water. Streptococcus lactis, Pseudomonas sp, and Bacillus subtilis are some species found to be best at decomposing plastics. These microbes may require specific environmental conditions such as optimum temperatures, special substrates, and certain pH values for efficient activity.
Plastic decomposition using microbes can be carried out in vitro or in vivo. In vitro methods had been the most efficient so far, also for vast polluted areas such as soils and marine ecosystems this is the most suitable. Potential problems are; the inability to control the environment conditions to provide the optimum conditions for microbial activity, the addition of foreign species to the environment, and some types of plastics like polythene are difficult to degrade. However, the advantages of utilizing bioremediation for plastic degradation is it being ecofriendly and able to target the elusive microplastics as well. Improvements to the bioremediation process such as developing microbes with a higher capacity at degradation using recombinant gene technology can be looked forward to.

Figure 1

Figure 1

References:
Bioremediation Technology for Plastic Waste. Mohd. Shahnawaz, Manisha K. Sangale and Avinash B. Ade, 2019
https://en.wikipedia.org/wiki/Bioremediation

Image courtesy:
Featured image:
https://opgplus.com/bioremediation-basics/
Figure 1
https://oceans.taraexpeditions.org/en/m/science/news/bacterial-degradation-of-synthetic-plastics/

Is bio fertilizer effectively working in agriculture?

What are bio fertilizers? Bio fertilizers are the substance which contains beneficial microbes, which helps in promoting the growth of plants and trees by increasing the supply of essential nutrients to the plants. It comprises living organisms which include mycorrhizal fungi, blue-green algae and bacteria. This practice of using beneficial microbes in agriculture started about 60 years ago. But the attention for this application has been increased in considerable amounts within the last decades due to continuous use of agrochemicals such as chemical fertilizers and pesticides in agriculture is detrimental to human health such as infant methemoglobinemia and which also cause ecological imbalance. The use of chemical fertilizer will also cause air and ground water pollution resulting from eutrophication. This practice also adversely affects the roots of the crops by making them unable to access nutrients. Therefore, there is a need to replace this conventional agricultural practice by implying a safer alternative to enhance the growth of the plants without affecting the agroecosystem.

In Sri Lanka, bio fertilizer is used in few cultivar plantations since unawareness of farmers. Also most bio fertilizers are being tested and held under research level for available crops such as rice, maize, coconut, rubber, big onions, vegetables in Sri Lanka. More research has been conducted for varieties of rice cultivation in Sri Lanka since the main food resource is rice. As examples, a project was done in 2012 for developing a biofilm biofertilizer for rice varieties such as “Suwandel”, “Ran thembili el” and “Kalu heenati”. According to the results, there was no significant difference in the yield between the farmer’s practice and the bio fertilizer only treatment. But, when coupled with the bulky organic material and bio fertilizer gave significantly higher grain yield. Therefore, both public and private sectors that are related to the agricultural field can introduce some biofertilizers for the farmers to evaluate the validity and suitability of the bio fertilizer with regard to the increasing crop yield. In addition to that, the ability of Azolla pinnata to grow and establish itself in rice fields was examined in several locations, falling within different agro-ecological zones of Sri Lanka. Under that project, Azolla that was grown with rice resulted in grain yields equivalent to fields that received 55 to 84 Kg N/ha of chemical nitrogen fertilizer and brought about a 50% reduction in weed growth.

In 2014 March, the first commercial biofilm biofertilizer product was launched for the tea Plantations under the brand name ‘Biofilm-T’ by Lanka Bio Fertilizers (Pvt) Ltd a subsidiary of Nature’s Beauty Creations. Now it is used widely in tea cultivation to increase yield and enhance tea plant growth rate, increase in capability to retain water makes tea plants more drought resistant. Biofilm-T successfully utilized amongst Small Holders in Makandura, Baangalthuduwa Estate-Batapola, Green Field Estate-Pitigala, Eduragala Estate-Kotagala Sri lanka.

Figure 1

Figure 1

At present, Lanka Bio Fertilizers (Pvt) Limited manufactures Bio fertilizer for Tea Plantations & maize under the brand name ‘Biofilm-T’ and ‘Biofilm-M’. Successful trials were conducted for Biofilm-M in Mahiyanganaya, Sri Lanka gave positive results as increasing the corn size and grain yield. Further, researches are being performed to develop commercial biofertilizers for other crops such as rice, chilies, coconut and vegetables since the main food necessity in Sri Lanka.

Figure 2

Figure 2

Biofilm biofertilizer gives large benefits to the country because each one ton of bio fertilizer can reduce 150 tons of chemical fertilizer dumped onto soils and save over Rs. 14 million in foreign exchange and over Rs. 10 million in fertilizer subsidy. Also bio fertilizer will help to preserve agrarian lands for future generations due to reduce the pollution. Not only to the country but also the farmers are given huge benefits by using bio fertilizer as those are cheaper than using only chemical fertilizer, it generates higher yields (15-30% increase) and improves quality of crop.

Therefore, the government should give their attention to the developing commercial biofertilizers to main crops in Sri Lanka, promoting the awareness and buying of bio fertilizer among local farmers.

References:

Nirodha Weeraratne1*, Gamini Seneviratne1(2012), Biofilmed bio fertilizers can replace bulky organic fertilizer handling in organic rice cultivation of Sri Lanka

S. A. Kulasooriya, W. K. Hirimburegama, S. W. Abeysekera, Azolla as a bio fertilizer for rice in Sri Lanka

http://www.biofilm.lk/about_us.html

Image courtesy:

Featured image:

Biofertilizer- Advantages, Types, methods of application and Disadvantages

Figure 1:

Figure 2:

file:///C:/Users/mega%20computers/Downloads/Biofilm%20Biofertilzier%20-%20A%20Success%20Story%20(4).pdf

Bacterial Pathogenicity

Pathogenicity refers to the ability of an organism to cause disease. It includes factors that contribute to disease or disorder and also talk about progression and maintenance. The state of being pathogenic is the pathogenicity. Pathogenicity expressed using microbial virulence and the degree of the organism’s pathogenicity. The genetic, biochemical and organism structural features that guide, the ability of pathogens to cause disease. This is called the determinants of virulence. The relationship between host and pathogen is dynamic. The pathogen and host both factors affect bacterial pathogenicity. Bacterial pathogens produce a wide range of molecules that bind the target host cell to facilitate a variety of different host responses.

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Figure 1

Many different genera bacterial pathogens share common mechanisms that help to adhere, invade, and cause damage to host cells and tissues. And also to survive host defense and establish infection. Microbial pathogenicity is essential to describe the molecular mechanisms of bacterial virulence and to the development of vaccines and other therapeutic agents for the treatment and prevention of infectious diseases. Bacterial virulence factors encoded in bacterial plasmids. This virulence factor genes integrate into the bacterial chromosome. Bacterial infection results from a disturbance in the balance between bacterial virulence and host resistance. The goal of bacteria is to multiply rather than to cause disease. Resistance to bacterial infections is enhanced by phagocytic cells and an intact immune system. The invasion of the host by bacteria then multiplies in close association with the host’s tissues. The capacity of a bacterium to cause disease reflects its relative pathogenicity.

Bacteria largely organized into three groups. They are Frank/Primary pathogens, Opportunistic pathogens and nonpathogens. Primary pathogens are considered to be expected agents of disease. Opportunistic pathogens become pathogenic following the disturbance or disruption of a host’s defense mechanisms. Nonpathogenic bacteria naturally exist within the host and cause disease to happen occasionally or never happen. Nonpathogens may change because of the adaptability of bacteria and the detrimental effect of modern radiation therapy, chemotherapy and immunotherapy on resistance mechanisms.

Virulence is the severity of a disease.

Figure 2

Figure 2

Number of physical and chemical features of the host help to act against bacterial infection such as antibacterial factors which secretions covering mucosal surfaces and rapid rate of replacement of skin and mucosal epithelial cells. Bacteria needed iron for growth. When bacteria penetrate the surface of the body, they find an environment in which they can get free irons to grow.

Virulence used a measurement for the pathogenicity of an organism. Adherence Factors, Capsules, Endotoxins and exotoxins which are secreted by pathogenic bacteria and siderophores to compete with the host for iron, which is an essential growth factor are called virulence factors. A healthy, intact immune system of the host can defend against bacterial infections. There are a number of factors that can affect host susceptibility. Most of the pathogenic bacteria multiply in tissue fluids such as respiratory system tissues. Medical science managed to make significant progress against pathogenic bacteria by using antibiotics. Antibiotics are any substances that inhibit the growth and replication of a bacteria. Most of the bacteria are harmless or often beneficial, but bacterial pathogenicity is important for the study of bacterial interaction with different hosts and how to prevent bacterial infections.

Image courtesy

Featured image:

https://blog.frontiersin.org/2018/07/06/new-section-on-molecular-bacterial-p athogenesis-open-for-submissions/

Figure 1:http://textbookofbacteriology.net/pathogenesis.html

Figure 2: https://www.coursehero.com/sg/microbiology/virulence/

References:

file:///C:/Users/a.k.computer/Desktop/Blog%20article/Bacterial%20Pathogen esis%20-%20Medical%20Microbiology%20-%20NCBI%20Bookshelf.html file:///C:/Users/a.k.computer/Desktop/Blog%20article/Mechanisms%20of%2 0bacterial%20pathogenicity%20Postgraduate%20Medical%20Journal.html file:///C:/Users/a.k.computer/Desktop/Blog%20article/What%20is%20Bacter ial%20Pathogenesis.html

What is Bacterial Biofilm?

Bacterial Biofilm
Figure 1: Bacterial Biofilm

The development of a biofilm consists of several stages, including the formation of a conditioning layer, bacterial adhesion, bacterial growth, biofilm maturation, and detachment. Different steps of microbial interactions with surfaces result in the formation of extracellular microbial structures. These mechanisms aid in initial binding, biofilm structure repair, and biofilm dispersal. Biofilm formation is thought to begin When bacteria detect environmental conditions that initiate the transition to life on a surface. Environmental signals such as nutrient content, temperature, moisture, pH, iron, and oxygen can all influence biofilm formation. Cells dedicated to adhesion upregulate complex adhesion genes within minutes of attaching to the surface. Attached bacterial cells produce new exopolysaccharide content to strengthen their adhesion to the surface and other bacterial cells in the expanding biofilm, transitioning from the reversible attachment to the irreversible adhesion process of biofilm formation. Biofilm related proteins aggrandize all primary attachments to nonliving surfaces and intercellular adhesion, according to studies on primary attachment, intracellular aggregation, and biofilm formation. Co-aggregation reactions play a part in the formation of biofilms in two distinct ways. The first way is Single cells in suspension, for example, readily concede and bind to genetically distinct cells in mature biofilms. The second method is Prior Co-aggregation, which involves suspending secondary colonizers and then adhering this co-aggregate to the expanding biofilm. By using a quorum sensing mechanism bacterium interact with each other within a culture in response to population density by using various chemicals known as signal molecules. The presence of macro-colonies with water channels indicates that the biofilm has matured. Detachment is a cell-to-cell connectivity process that is regulated by attached cell populations.

Steps of bacterial biofilm formation
Figure 2: Steps of bacterial biofilm formation

A bacterial biofilm state can be needed for a variety of reasons. For instance, biofilm can increase bacteria’s resistance to harsh environmental conditions. Bacteria can bind to a surface or tissue to prevent being washed away by water or the bloodstream. Oral biofilms can withstand repeated, high shear forces. Biofilm cells are 1000 times more resistant than planktonic cells. Also, the EPS matrix defends bacteria cells in deeper layers from antimicrobial agents, most likely by limiting antimicrobial agent diffusion. Biofilms limit bacterial mobility and increase cell density, creating an ideal condition for eDNA (plasmid) exchange (via conjugation), which encodes for antibiotic resistance in some situations. The rate of horizontal gene transfer in biofilms is substantially higher than in planktonic cells.

Biofilms play a significant role in disease transmission and persistence in humans. Many bacterial infections, such as chronic lung, wound, and ear infections, are caused by biofilms. These diseases are difficult to detect and treat. Food contamination and biofouling in the industry are the other negative aspects of biofilms.

Controlling biofilm production is difficult because microorganisms in biofilm evolve different mechanisms in different environments; however, there are successful methods for controlling biofilm formation. To control bacterial adhesion, antimicrobial agents (antibiotics, oxidants, and biocides), surface modifications, and electro-assisted methods can be used. Biofilm detectors, such as mechatronic surface sensors, track bacterial colonies and aid in biofilm monitoring during the early stages of growth etc.

Biofilms, on the other hand, have a beneficial role in bioremediation. Application in this field is rare since it is still understudied. Gene transfer within the bacterial population can be used to target biofilm applications of bioremediation.

Is Gluten bad for you ?

Do you think that normal people should have a gluten-free diet? What’s the real deal with gluten? Actually, the label “gluten-free” has been adopted by many baked food producers in western countries because it is a good marketing idea just as the label “organic”. The reason for producing gluten-free food is due to the health risks that gluten consumption poses on a certain percentage of the human population. This article will delve into the events that lead to the “gluten-free” label.

In Asian countries like Sri Lanka, the staple food over many generations had been rice. However, consumption of bakery products such as bread, buns, cake, sandwiches are on the rise, merely because of the busy lifestyle of consumers. This is mostly the case in urban areas where it is normal for both the parents of a family to be employed. The main ingredient of baked foods is wheat. One of the main differences in terms of nutritional content between rice and wheat is the presence of gluten in wheat. This is an important difference because the reaction of the human digestive system to gluten can be different from an individual to individual.

Gluten is naturally present in grains such as wheat, rye and barley. Gluten is the general term given to wheat proteins, especially to the two proteins glutenin and gliadin. It is the gluten proteins that provide the elastic nature to bread and other types of baked products. It is also the reason for the difficulty of preparing baked products from gluten-free grains. Actually, the name ‘gluten’ is derived from the glue-like property of wet wheat dough.

As mentioned before, people react differently to gluten. Some people are “gluten-sensitive” and experience symptoms such as swelling, gastric discomfort, bloating, constipation and other mild or severe symptoms from consuming food containing gluten. Celiac disease is an autoimmune disorder where the immune system treats gluten as a foreign invader and attacks gluten in the gut along with the lining of the small intestine. Symptoms of celiac disease can vary and range from digestive discomfort to skin rashes. Long term effects such as anemia, nerve system disorders, cancer and infertility can occur as well. There are other diseases that occur due to gluten consumption such as wheat allergy, non-celiac gluten sensitivity and dermatitis herpetiformis.

Celiac disease can be identified by blood tests for antibodies or biopsy of the small intestine. However, other symptoms and diseases due to gluten intolerance are difficult to detect. Therefore, western doctors advise the patients to observe for any differences in the body when consuming a gluten free diet and then observe for any changes that occur after gluten is reintroduced into the diet. From such methods, a person can deduce whether certain symptoms such as joint pain and inflammation are actually the results of gluten consumption or not.

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Many people in countries like America have already converted to “gluten-free” diets where they consume grains that do not contain gluten such as rice, oats, quinoa, millet and sorghum. Even though whole wheat grains are a good source of nutrients and vitamins, the risk posed by gluten outweighs all positive advantages of consuming gluten-rich grains, especially for gluten intolerant people. However, it does not mean that gluten is unhealthy. For people who are not sensitive to gluten, grains such as wheat are a good source of daily nutrition. People who consume vegan diets often use gluten as a source of protein. Therefore, the general claim that gluten is bad for health is not always correct. However, it is essential to be precautious when shifting to a totally different food source.

References:

A Study on Sectoral Difference of Buying Behaviour of Consumers towards Bakery Foods with Special Reference to Balangoda Divisional Secretariat Division. Kanthe et al, 2014.

https://www.medicalnewstoday.com/articles/318606#gluten-intolerance

https://www.hsph.harvard.edu/nutritionsource/gluten/

Image courtesy :

Featured image:

http://www.todayifoundout.com/index.php/2014/03/whats-deal-gluten/

Figure 1:

https://www.diabetesjuntosxti.mx/nutricion/articulos/ventajas-desventajas-una-dieta-libre-gluten/2017/09/

Timid Treetops – How do plants maintain ‘social distancing’?

Social distancing is quite familiar for us these days because of the COVID-19 pandemic. But have you ever heard that trees are maintaining social distancing way before COVID-19? Amazing, isn’t it? This phenomenon is known as ‘crown/canopy shyness’, where the treetops avoid touching each other by creating channel-like boundaries among themselves at the canopy level. The visual aspect of crown shyness is breathtakingly artistic, and it resembles the bird’s eye view of rivers! You might have seen crown shyness which looks like a giant jigsaw puzzle when you look up at the sky in some forests.

This mind-blowing natural phenomenon was firstly described in the 1920s and the term ‘Tree Shyness’ was introduced in the 1950s by the botanist Maxwell R. Jacobs. Since then, this has been studying extensively for decades in order to investigate the reason for the occurrence of this ‘social distancing’ among trees. Other than some hypotheses and theories which have been suggested to explain crown shyness, the exact physiological basis behind this mysterious behaviour of trees is not unraveled yet.

Crown shyness does not occur between all types of trees. Most commonly, it occurs between the trees of the same species. However, there are some incidents where crown shyness occurs between trees of different species as well. More interestingly, crown shyness can also be seen between independently swaying branches of a single tree.

Figure 1: Bird’s eye view of forest canopy with crown shyness

Figure 1: Bird’s eye view of forest canopy with crown shyness

But how do trees have their own space? Some scientists suggest that shyness gaps can be formed due to the abrasion between the branches by wind. However, it has been discovered that the wind is not the only reason behind crown shyness because the studies conducted in Malay camphor trees (Dryobalanops aromatica) have not shown any abrasions between trees. Furthermore, crown shyness was not significantly prominent in trees which are exposed to high winds than that of in less windy areas. Hence, scientists have suggested another hypothesis where the trees stop growing by sensing light through their growing tips when they are near to the branches of the neighbouring tree. There is another hypothesis which suggests the influences exerted by individual trees on each other result in shyness gaps. These two hypotheses focus on minimizing competition among trees for resources such as light which is essential for photosynthesis. In addition, there is one more hypothesis which explains the formation of these gaps in terms of allelopathy. This hypothesis is quite interesting because if this is true, it means trees communicate with each other using chemical compounds and notify the neighbouring trees to halt their growth towards them. It is believed that the real reason behind crown shyness is quite a combination of all these hypotheses rather than a single specific theory.

Amidst all these theories and hypotheses explaining the potential mechanisms of the occurrence of crown shyness, there are some other suggestions which describe the benefits of this peculiar phenomenon. Shyness gaps allow light to reach the forest floor nurturing the lower canopy trees including shrubs and ground cover. Moreover, trees can minimize the effects from wind, harmful flightless insects and pathogens by avoiding physical touches among each other. Trees can also avoid the spread of invasive lianas by having crown shyness.

Figure 2: Crown shyness of trees

Figure 2: Crown shyness of trees

These natural phenomena always remind us how astonishing and mysterious our mother nature is. Being sessile and silent, isn’t it amazing how trees respond to each other and communicate among themselves? See how respectful and cooperative they are! So next time, when you are walking through a forest, do not forget to look up at the sky and enjoy the magnificent view of crown shyness. And also, spare some time to capture an instagrammable photo of this panoramic spectacle of timid treetops.

References:

https://www.treehugger.com/what-is-crown-shyness-4869713

https://www.nhm.ac.uk/discover/crown-shyness-are-trees-social-distancing.html

https://daily.jstor.org/the-mysteries-of-crown-shyness/

https://www.nationalgeographic.com/science/2020/07/tree-crown-shyness-forest-canopy/

Image courtesy:

Featured image: https://www.nhm.ac.uk/content/dam/nhmwww/discover/crown-shyness/crown-shyness2-full-width.jpg

Figure1:https://www.richardx.co.uk/wp-content/uploads/2019/11/20191103-DJI_0733.jpg

Figure 2: https://www.jasonferrellphotography.com/images/xl/Ascension.jpg

Why Should We Say Yes to Indoor Plants?

There is no doubt that you all love to have plants in your home garden, but usually, people are wondering whether to say yes to indoor plants. You may have seen beautiful pictures of interior designs with indoor plants while surfing through the internet, yet worry to have one in home. Is it good to have them inside houses? This is the most frequently asked question that comes to the stage when talking about indoor plants? After reading this article you would probably set your mind to say ‘yes’ for indoor plants. 

The most important benefit of the indoor plants is that they can purify the air. Did you know that the pollutants can stay even in air inside of buildings? Yes, sometimes it is more than the air outside. Indoor plants help to purify the polluted air by absorbing the toxic pollutants. They will assure that you are breathing good air. They do a really good job, don’t they? 

Another fact that you should know is, indoor plants can reduce noise levels. This is important in office buildings, since the plants help to reduce noise which can create a calm and satisfying environment for employees without distractions. This will help even to reduce the stress levels in the working environment thereby improving the performance of employees. 

Indoor plants offer you both physical and psychological health benefits. There is scientific evidence on the ability of indoor plants to reduce stress levels and anxiety of people. These indoor plants will help you to recover fast from illnesses and injuries. Studies have shown that the patients who stayed surrounded by indoor plants required less pain medication, had a lower blood pressure and heart rate, and also felt less anxiety and fatigue than patients without greenery inside their rooms. What a friend to keep inside your home!

In general, people love to see green plants which set them a peaceful mind. Thus, it would be a visually meditative experience for you to work in a place surrounded with green plants. Not only that, green shades of indoor plants will add more beauty with a natural look to your home or the workplace. It will create a fresh and peaceful environment for both you and the visitors.

Figure 1: Different indoor plants

Figure 1: Different indoor plants

Now think why not to admire indoor plants for their great service.
However, every plant is not suitable for indoor planting.  Each indoor
mate may have unique qualities. Therefore, choose the plants wisely.
Plants are living organisms. They can sense, so talk with them, touch
them, and admire them. Show some love to your indoor mates and see the
difference.

References

https://www.ambius.com/indoor-plants/office-plants/benefits/

https://www.prevention.com/health/g27586276/benefits-of-indoor-plants/

https://www.researchgate.net/publication/43344334_The_Investigation_of_Noise_Attenuation_by_Plants_and_the_Corresponding_Noise-Reducing_Spectrum

Image courtesy

Featured image:  https://unsplash.com/photos/S7viz8JWxwY

Image 1: https://www.admiddleeast.com/public/styles/full_img/public/images/2019/11/21/Osofsky_Oct19-571.jpg?itok=mBI07ilg

Bioinformatics in Plant Science

What is Bioinformatics?

Some of you may not be familiar with the term Bioinformatics. Bioinformatics is the study of biological data using information and communication tools. It includes mathematics, statistics and computer algorithms. It is merely not biology, but a combination of many fields of science. The fundamental purpose of bioinformatics is analyzing biological data using computer programs. Programming languages are used as tools in bioinformatics such as Python, C and C++. 

How to apply Bioinformatics in Plant Sciences?

 Single gene analysis is the most fundamental molecular level analysis in plant bioinformatics. All genes in the plants can be analyzed using single-gene analysis. Furthermore, bioinformatics is used to identify biochemical pathways in plants to understand higher-level functions in plant systems. Protein modeling was a great challenge in the past. Thanks to bioinformatics, most plant proteins can be modeled now using bioinformatics tools. 

Role in Plant Research

 There are many roles of bioinformatics in plant research. It helps many research areas in crop improvement such as improving nutritional quality, development of drought-resistant and insect resistant varieties. In most of these procedures, bioinformatics techniques are used for sequencing data processing, data organizing and screening processes. There are many databases regarding plant genes that aid in plant-based research with the use of bioinformatics techniques. NCBI (National Center for Biotechnology Information), KEGG (Kyoto Encyclopedia of Genes and Genomes) and EST (Expressed Sequence Tags) are well-known databases which are generally used to find out information about the gene sequences using developed computer programs.

Why do we learn Bioinformatics?

With the current pandemic situation of Covid-19, Bioinformatics and Molecular Biology have caught more attention of both scientists and the general public. Bioinformatics is used to find out the genetic deformities in plants and animals, discover new medical treatments and collect unrevealed data about the genomes of plant and animal life. Currently, many kinds of research are happening all around the world, but the world needs more researchers in the field of bioinformatics. This novel field will be interesting for undergraduates who are interested in both biology and computer science. If you are a postgraduate student willing to do your PhD on bioinformatics, there are numerous opportunities throughout the world. Therefore, a long journey awaits in front of the bioinformatics enthusiasts in the future world!

Image courtesy:

https://www.wits.ac.za/media/wits-university/course-finder-images/dna.png

References:

  1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1122955/

  1. http://jpbb.samipubco.com/

Intelligent Plant Life – 1

When you hear the term, “intelligence”, most of the time you think about it in an anthropogenic centred way. Yes, humans have a complex brain with interconnected neural networks. As a result, humans have many abilities such as making their own decisions, problem-solving, reasoning, learning and memorizing. Not only humans, other animals also have a different kind of neural systems. Even though some animals do not show well-developed brain organization, they have different scales of neural cells assemblies. These animals can manipulate their behaviour by responding to stimuli to overcome environmental challenges. They perceive signals, respond, learn and memorize the experiences in their lifetime. The collection of all these cognitive abilities can be considered altogether as intelligence. However, there is no universal definition for it. Do you think that intelligence only limits to humans and animals?

Figure 1

Figure 1

Recent studies suggest that intelligence may exist even in plants. It is a bit controversial because many of us think that intelligence connects with neural systems. In the animal aspect, it is true. Plants do not have neurone systems. They are silent, sessile organisms. However, we cannot say the silent green world is not intelligent! They perceive external signals and respond to them. This response can be considered as the behaviour of plants. Unlike the muscular movement of animals, plant behaviour is related to the changes in growth. Even though muscular movements are powerful and fast, growth responses are slow and below our visual capacity to see it without measuring. Initial cell signalling is associated with action potentials and changes in cytoplasmic Ca2+ levels like animals. The speed of the process differs between plants and animals. Intracellular communication exists in plants like animals. Plants use phytohormones such as auxins, gibberellins, cytokinin, abscisic acid, ethylene, salicylic acid and jasmonate. Hormone-based regulation also exists in animals. In plants, plasmodesmata enable movement of proteins, nucleic acids and other small molecules. They act as channels for the cell to cell communication. Physiological alterations occur in plasmodesmata after exposing to anaerobic or osmotic stress as adaptation. Similarly, the dendrites in neuronal cells alter to amplify the communication pathway during the learning process in animals. Thus, we cannot underestimate the abilities of the plants.

Dr. Monica Gagliano is a biologist who studied plant behaviours and their cognitive abilities. During the panel discussion at the World Science Festival 2019 titled “Intelligence without brains”, she explained about the experimental evidence related to the intelligent plant behaviour. She conducted several researches related to plant communication, plant memory and learning capacity. The rest of the article gives you a brief explanation about one of her studies about plant learning ability.

Figure 2

Figure 2 : Mimosa pudica plant

For the experiment, a sensitive plant, Mimosa pudica was selected due to its ability to show leaf-folding reflux as a response to physical disturbance. Other than that, this defensive response can easily be used for studying the behavioural phenomenon called habituation. Habituation is an adaptive process that enables organisms to extract important information from the environment while ignoring stimuli and events that are repeatedly proven to be irrelevant. It is a simple form of learning. Remembering the previous experience is crucial for the habituation process. Learning and remembering are features of intelligence. Thus, habituation represents a basic level of intelligence. To determine the degree of habituation, she designed special plant-dropping set up for training the Mimosa plants. These plants were subjected to seven consecutive trains of 60 drops with 5 or 10 seconds inter-stimulus intervals.

Figure 3

Figure 3: The plant-dropping set up

Here, they observed that Mimosa leaves reopened even before the first train of droppings was completed. By the end of the training, leaves completely remain opened. The leaf-folding reflux habituates rapidly. It means that Mimosa plants can show learning behaviour! Now, are there any questions coming into your mind? You can say that this phenomenon can be a result of energy depletion or fatigue. To answer this question, they placed trained plants on a shaker for giving a new stimulus. If the stopped leaf-folding reflux is caused due to fatigue, these plants would not be able to respond to new stimuli. Surprisingly, Mimosa leaves showed leaf-folding reflux again. There is no doubt that Mimosa plants can learn! Dr Monica Gagliano also showed that habituation could persist for about a month. It indicates that Mimosa plants can remember the details about stimuli by an unknown mechanism. These plants learn to ignore non-harm stimuli. This behaviour minimizes energy loss and maximizes light capturing. They change their normal behaviour based on the novel condition for optimum survival.

What do you think about plants now? Are these plants intelligent or not? Green life has a kind of intelligence, which needs to be studied more in the future. Let’s think differently about the silent green world. Then you will realize the secrets that exist within plants!

References
https://link.springer.com/article/10.1007/s00442-013-2873-7

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4845027/

https://academic.oup.com/aob/article/92/1/1/177536

https://www.bluesci.co.uk/posts/a-case-for-plant-intelligence

Image courtesy:
Featured Image: https://cdn.the-scientist.com/assets/articleNo/66101/aImg/32588/plant- consciousness-thumb-l.png

Image 01: https://media.wnyc.org/i/1860/863/c/80/1/3_brain-vs-plant.jpg

Image 02: https://lh3.googleusercontent.com/proxy/2dzAOZfl4OsDsXUorB5gXwvQHgXK1tS3wHToWkbarN9UKwpi15fn_7oVNPYCtCH-U85si6ipJ3EnaKamvce_CVbbCA90Mx3dO0xD6dyaKm6k0kE2TvUskv5TYbM

Image 03: https://www.nationalgeographic.com/content/dam/science/phenomena/curiously-krulwich/rights-exempt/files/2015/12/2GIF_Plant-Drop.gif

The Science Behind The Colours In Nature

Do you know how the ancient man added colours to their clothes, artworks and food? Have they obtained different types of colours either from plants, animals or microorganisms? Why do plants or animals show a colour?

According to historical records, since ancient times, man has been interested in colours. Early man has obtained different types of colours originated from plants, certain invertebrates, micro-organisms and minerals. Out of them, plant-based natural dyes were the most common. Natural pigments are present in the cytoplasm in different forms. The green pigments called chlorophylls that give the green colour to leaves are present in chloroplasts. The yellow to red pigments called carotenoids are the reason for the colour of ripening fruits and flowers. They are present in chromoplasts. Besides, there are few water-soluble pigments which are present in the vacuole as well.

As we all know, chlorophyll is the main colourant in almost all of the plants in the plant kingdom which facilitates the photosynthetic mechanism. The varying amounts of conjugated double bonds in the pigment is the place of the light absorption. It is also an efficient antioxidant, which

reduces oxidative stress in cells caused by UV light exposure and several other stresses. Carotenoids are tetraterpenoids that assist light-harvesting as accessory pigments. Fruits such as tomatoes (Solanum lycopersicum) and watermelons (Citrullus lanatus) contain red-carotenoid pigments. They are rich in lycopene and B-carotene. Moreover, some carotenoids (neoxanthin and violaxanthin) act as precursors for the biosynthesis of Abscisic acid.

Figure 1&2: Carotenoid pigmented fruits

The majority of plant-derived natural pigments are secondary metabolites. They do not have a direct role in growth and development. However, these are important for vital functions that ensure plant survival. Pigments are a reason for the attraction of pollinators and deterrence of predators. Further, scientists believe that pigments have a significant role in the coexistence and coevolution of species allowing interactions. Indigo is a well-known blue dye extract from Indigofera sp. throughout the world while Madder (Rubia tinctorum) gives a shade of red. Saffron (Crocus sativus), turmeric (Curcuma longa), safflower (Carthamus tinctorius) and marigold (Tagetes erecta) are some yellow pigment producing plants.

Anthocyanins are glycosylated polyphenolic compounds which represent a large group of plant secondary metabolites. These are widely used in the food industry as an alternative to synthetic colourants due to their health benefits. It is also safe for human consumption. Interestingly, anthocyanins can serve as a pH indicator due to their ability to change colour based on the pH changes in the intravacuolar environment. In acidic environments, it shows a reddish-pink. The colour changes towards green colour in an alkaline medium. It is reddish-purple in neutral solutions (pH=7). Pigments such as astaxanthin and lycopene are used as dietary supplements.

Figure 3

Figure 3: Anthocyanin pigmented flowers e.g.: Butterfly pea flowers (Clitoria turnatea)

Pigmentation is a useful strategy of signalling and protection in animals. They show camouflage and mimicry using different pigmentation for protecting itself. Several pigments also were extracted from animals such as cochineal insect (Dactylopius coccus), lac insect (Kerria lacca), kermes and shellfish.  Mycobacterium sp. and Staphylococcus aureus are some pigment-producing microorganisms. Some species of bacteria produce pigments continuously while others produce in response to environmental stresses. In response to low iron stress, carotenoids are accumulated in some algal species like Synechococcus species.

Natural dyes were the only source of colour for fabrics, leather and other materials until synthetic dyes were discovered in the eighteenth century. At present, a combination of genetic engineering in biosynthetic pathways of plant pigments and hybridization may lead to advances in commercial applications related to natural dyes. Hence, it is high time to think about sustainable methods along with a scientific approach to develop natural dyes from potential sources.

Microplastics- the yet invisible macro problem in the world.

Plastics as we all know are a wide range of synthetic or semi-synthetic organic compounds that are used to form a large number of useful objects for day to day requirements. The most talked about topic on plastics is plastic pollution. Since plastics are highly durable polymers, it takes hundreds of years to decompose and the plastics thrown away, linger in the environment for long periods of time. However not only the environment, animals and plants can also get ‘polluted’ by plastics. This is due to microplastics entering plants through water absorption by roots or ingestion of food along with microplastics by animals. This article is an introduction to microplastics, how likely microplastics affect human lives and the environment, and the methods of remediation to this problem.

Microplastics are small pieces of plastic less than 5 mm in length which occur in the environment as a consequence of plastic pollution. Many people are of the belief that microplastics result from degradation of used plastic items, however, there are two types; the primary and secondary microplastics. Primary microplastics are tiny plastic particles designed directly for commercial use such as microbeads in some abrasive toothpastes, skin scrubs, microfibers in textiles, and are released to the environment after usage. Secondary microplastics are tiny particles resulting from the breakdown of larger plastic items such as toys, polythene bags and bottles.

Microplastics are persistent and difficult to degrade into individual atoms due to their small size. Therefore, they get accumulated in almost all the ecosystems on earth from deep oceans to agricultural soils and even high up in mountains, because the smallest microplastics can form dust particles. They have been found in the tissues of plants, aquatic fish, and land animals as well. Scientists have found microplastics in human stool, tissues, and organs. Even though the effect of microplastics to humans is not yet understood, studies have shown that microplastics in the diet of aquatic fish, result in generating less energy for the fish because of its indigestibility, ultimately causing death. The accumulation of microplastics can result in major loss of biodiversity in the years ahead.

Microplastics exist in the air we breathe, the food we eat, as well as in our bodies. It was estimated that the ocean surface contained 5.25 to 50 trillion pieces of microplastics in the year 2014. The atmosphere holds tons of microplastic fibers and therefore, found in the air we breathe. According to a research conducted in Greenland in 2019, it was found that people consume at least 50,000 microplastic particles per year along with food.

Due to the continued worldwide use of plastics, used plastics are discarded into landfills, which causes more and more microplastics being released to the environment. The actions that can be taken to mitigate accumulation of microplastics and removal from the ecosystems are of various methods. Due to the small size of microplastics, they cannot be physically separated from the environment. The simplest method of remediation is to stop the use of plastics altogether, especially the use of primary microplastics in commercial products. However, the plastics in the landfills will degrade and add more secondary microplastics into the environment.

The immune system has been evolved to protect the body from any foreign organism or particle since, foreign objects are usually unfavorable for the functioning of the body. There is no doubt that microplastic accumulation in animal tissue will result in adverse reactions or alter the normal functioning of the body due to the formation of impenetrable barriers. Therefore, even if environmental pollution may not be a life-threatening aspect to many people, the possibility that microplastics could remain wedged into human tissues must make it a concern to many. This problem cannot be ignored and should not be ignored.

Therefore, the most successful method of remediation is to use microorganisms capable of degrading microplastics. There are several bacterial species such as Bacillus amyloliquefaciens, B. subtilis, B. cereus and Pseudomonas putida that are capable of degrading microplastics. In addition, there are microplastic degrading fungal species such as Pestalotiopsis microspora and Aspergillus flavus. Pestalotiopsis microspora can degrade polyurethane, even under low oxygen conditions. These microbes secrete hydrolytic enzymes, which depolymerize polyurethane. Usage of microplastic degrading microbes would be a promising solution for reducing microplastic pollution.