Climatic change is a significant concern for the future of our planet, and one potential solution to mitigate its effects is plant-based carbon sequestration. This article will discuss the role of plants in carbon sequestration and how they can contribute to reducing atmospheric greenhouse gas levels. The fundamental process of carbon sequestration in plants begins with photosynthesis, a complex biochemical mechanism that goes beyond just absorbing carbon. Photosynthetic organisms, primarily plants, utilize solar energy to convert atmospheric carbon dioxide (CO2) into organic compounds, releasing oxygen as a byproduct. In recent years, researchers have delved deeper into understanding the intricate molecular processes involved in photosynthesis, aiming to enhance the efficiency of carbon fixation and storage.

Advancements in plant genomics have paved the way for the identification and manipulation of key genes responsible for photosynthetic performance. Genetic engineering techniques, such as CRISPR-Cas9, offer the potential to create crops with increased photosynthetic rates and improved carbon sequestration capabilities. This targeted approach aligns with the broader goal of developing climate-resilient and high-yielding plant varieties that can contribute significantly to minimize atmospheric carbon levels.

Figure 1: A schematic showing carbon sequestration

Effectiveness of Different Ecosystems for Plant-Based Carbon Sequestration

The effectiveness of plant-based carbon sequestration varies across different ecosystems, each presenting unique opportunities and challenges. Understanding how diverse ecosystems contribute to carbon sequestration is crucial for developing targeted strategies that optimize their potential.
Blue carbon refers to the carbon captured and stored by the world’s ocean and coastal ecosystems, such as mangroves, seagrass meadows, and tidal marshes (Figure 2). These ecosystems play a crucial role in climate change mitigation and adaptation, as they sequester and store carbon at a faster rate than terrestrial forests.

1. Forests and Woodlands:
Forests are among the most effective ecosystems for carbon sequestration due to the large biomass of trees and the long-term storage potential in woody tissues. Old-growth forests, in particular, play a vital role in sequestering carbon over extended periods. However, careful consideration is required to balance the carbon sequestration benefits with biodiversity conservation, as monoculture plantations may not provide the same ecological services as diverse natural forests.

2. Grasslands and Wetlands:
Grasslands and wetlands, while often overlooked, contribute significantly to carbon sequestration. Grasses capture carbon in their roots and soil, and wetlands act as carbon sinks due to the anaerobic conditions that slow down the decomposition of organic matter. Sustainable management of these ecosystems, including rotational grazing and wetland restoration, enhances their carbon sequestration potential.

3. Mangroves and Coastal Ecosystems:
Mangroves and coastal ecosystems are highly effective at sequestering carbon, both in above-ground biomass and in the sediment below. The unique conditions in these areas, characterized by saline water and waterlogged soils, create an environment where organic matter decomposes slowly. Conservation and restoration of mangroves not only contribute to carbon sequestration but also provide critical habitat for marine life and act as buffers against coastal erosion.

4. Agricultural Lands:
Agricultural lands, when managed sustainably, can contribute to carbon sequestration through practices such as cover cropping, agroforestry, and no-till farming. These approaches enhance soil organic carbon content, improving soil structure and fertility. Precision agriculture technologies further optimize the efficiency of these practices, ensuring that agricultural lands become part of the solution to climate change.

5. Urban Green Spaces:
Urban green spaces, including parks and green belts, play a role in carbon sequestration within urban environments. While the contribution may be smaller compared to larger ecosystems, the collective impact of strategically placed green spaces can help mitigate the urban heat island effect and enhance local air quality. Incorporating trees and vegetation into urban planning fosters a balance between carbon sequestration and human well-being.

6. Alpine Ecosystems:
Alpine ecosystems, characterized by high-altitude regions, contribute to carbon sequestration through the slow decomposition of organic matter in cold and oxygen-deprived conditions. As temperatures rise due to climate change, there is concern about the potential release of stored carbon from these ecosystems. Sustainable conservation practices are essential to maintain the effectiveness of alpine ecosystems in sequestering carbon.

Figure 2: Blue Carbon

Integrating Ecosystems for Synergistic Carbon Sequestration

Recognizing the diverse contributions of different ecosystems, an integrated approach that combines afforestation, reforestation, and sustainable land management practices is paramount. Synergies between ecosystems can amplify overall carbon sequestration benefits. For example, agroforestry practices that integrate trees into agricultural landscapes not only sequester carbon in biomass but also enhance soil carbon levels.

Furthermore, the preservation of natural ecosystems and the restoration of degraded areas contribute to maintaining biodiversity, ecosystem resilience, and the overall health of the planet. Climate-adaptive strategies, as discussed earlier, should consider the specific characteristics of different ecosystems and tailor interventions accordingly.

The effectiveness of plant-based carbon sequestration is intricately linked to the diverse ecosystems that cover our planet. By understanding and harnessing the unique strengths of each ecosystem, we can develop comprehensive strategies that maximize the potential of plant-based carbon sequestration, contributing to a more sustainable and resilient future.

Advanced Techniques in Plant-Based Carbon Sequestration

1. Enhanced Afforestation and Reforestation Strategies

While afforestation and reforestation are established methods for carbon sequestration, ongoing research is focused on enhancing their efficacy. Novel approaches include the identification and cultivation of tree species with accelerated growth rates and high carbon sequestration potential. Genetic modification techniques are explored to develop trees with increased biomass and improved resistance to environmental stressors, thereby maximizing carbon absorption and storage.

Additionally, precision forestry, aided by satellite imaging and machine learning algorithms, allows for optimal placement of trees based on soil conditions, climate patterns, and local ecological factors. This strategic placement not only enhances carbon sequestration efficiency but also minimizes potential negative impacts on local biodiversity.

2. Advanced Bioenergy with Carbon Capture and Storage (BECCS)

Continued advancements in BECCS technology are crucial for its integration into comprehensive carbon sequestration strategies. Research is underway to improve the efficiency of CO2 capture methods and explore alternative storage solutions, such as utilizing captured carbon for the synthesis of valuable products or converting it into stable mineral forms. These innovations aim to address the economic feasibility and sustainability concerns associated with BECCS.

Furthermore, the exploration of alternative biomass feedstocks, such as algae and fast-growing perennial grasses, is underway to enhance the carbon capture potential of bioenergy systems. Integrating these feedstocks with traditional afforestation and reforestation practices creates a synergistic effect, amplifying the overall carbon sequestration capacity.

3. Precision Soil Carbon Sequestration Practices

Advancements in agricultural practices are crucial for optimizing soil carbon sequestration. Precision agriculture, facilitated by technologies like remote sensing and data analytics, enables farmers to tailor their approaches based on specific soil characteristics and environmental conditions. This approach includes the utilization of cover crops that not only enhance carbon sequestration but also contribute to improved soil fertility and water retention.

In addition, the incorporation of mycorrhizal fungi into agricultural ecosystems shows promise in boosting plant nutrient uptake and, consequently, increasing biomass and carbon sequestration. Research is ongoing to understand the symbiotic relationships between plants and fungi, with the aim of developing customized microbial solutions for different crops and soil types.

Figure 3: Soil Carbon Sequestration

Addressing Challenges and Expanding Opportunities

1. Sustainable Land Management and Conservation

To address the challenge of requiring large land areas for plant-based carbon sequestration, sustainable land management practices are imperative. This involves identifying marginal lands unsuitable for conventional agriculture and utilizing them for afforestation, reforestation, or bioenergy crop cultivation. Additionally, integrating carbon sequestration initiatives with conservation efforts can help preserve biodiversity by creating corridors for wildlife movement within these managed landscapes.

2. Long-Term Monitoring and Adaptive Management

Ensuring the long-term effectiveness of plant-based carbon sequestration methods necessitates robust monitoring systems. Advances in remote sensing technologies, coupled with on-the-ground sensor networks, enable continuous tracking of carbon stocks in forests and soils. This data-driven approach allows for adaptive management strategies, where interventions can be adjusted in real-time based on changing environmental conditions and the effectiveness of implemented measures.

3. Climate-Adaptive Strategies

Recognizing the influence of climate, soil type, and local policy on the effectiveness of carbon sequestration methods, researchers are developing climate-adaptive strategies. These involve tailoring plant-based carbon sequestration approaches to specific climatic zones and soil conditions, optimizing their performance in varying environmental contexts.

Figure 4: Problems related to BECCS

Conclusion

The potential of plant-based carbon sequestration methods to mitigate climatic change is vast, and ongoing scientific advancements are expanding their capabilities. Enhanced afforestation and reforestation strategies, advanced BECCS technologies, precision soil carbon sequestration practices, and sustainable land management approaches are crucial components of a comprehensive solution. By addressing challenges and leveraging emerging opportunities, plant-based carbon sequestration can play a pivotal role in combating the escalating threat of climatic change, contributing to a more sustainable and resilient future for our planet. Continued interdisciplinary research and international collaboration are essential to fully unlock the potential of these innovative approaches.
Kosala Abeykoon
3rd Year

References :
I. Tdus. (2021). Biological Carbon Sequestration. UC Davis. https://www.ucdavis.edu/climate/definitions/carbon-sequestration/biological
II. Soil-based carbon sequestration. (n.d.). MIT Climate Portal. https://climate.mit.edu/explainers/soil-based-carbon-sequestration
III. Lorditch, E. (2022). Capturing carbon with crops, trees and Bioenergy. MSUToday. https://msutoday.msu.edu/news/2022/capturing-carbon-with-crops-trees-and-biomass
IV. Thomas, S. T., Shin, Y., La Clair, J. J., & Noel, J. P. (2021). Plant-based CO2 drawdown and storage as SiC. RSC Advances, 11(26), 15512–15518. https://doi.org/10.1039/d1ra00954k
V. Kell, D. B. (2012). Large-scale sequestration of atmospheric carbon via plant roots in natural and agricultural ecosystems: why and how. Philosophical Transactions of the Royal Society B, 367(1595), 1589–1597. https://doi.org/10.1098/rstb.2011.0244

Image Courtesies:

Featured Image: https://calrecycle.ca.gov/wp-content/uploads/sites/39/2022/02/biosequest.png?w=827
Content Image 1: https://upload.wikimedia.org/wikipedia/commons/thumb/b/b5/Carbon_sequestration-2009-10-07.svg/1024px-Carbon_sequestration-2009-10-07.svg.png
Content Image 2: https://blog.wcs.org/photo/wp-content/uploads/2021/11/blue-carbon-poster-for-WV-920×650.jpg
Content Image 3: https://ejpsoil.eu/fileadmin/projects/ejpsoil/Themes/CO2_cycle.jpg
Content Image 4 : https://www.geoengineeringmonitor.org/wp-content/uploads/2021/11/BECCS_diagram_4web.jpg

Plants host diverse communities of microorganisms, also known as the microbiome, which colonizes various parts of host plants such as the rhizosphere, phyllosphere, and endosphere. The microbiome includes protists, fungi, bacteria, viruses, nematodes, etc. This highly complex assemblage of microorganisms has an important role in plant growth and health as well as in improving the productivity of crops by forming complex co-associations with plants. The plant-associated microbial communities confer multiple beneficial advantages to their host plants through nutrient acquisition, growth promotion, pathogen resistance, and environmental stress tolerance. Nowadays, a considerable amount of information is available on the structure and dynamics of the plant microbiome. The functional capacities of the isolated microbes have been identified using novel technologies.

The world population is estimated to rise to 9.5 billion by 2050, leading to high food demand. The availability of limited fertile land, urbanization, and climate change are some of the major constraints for the productivity of many crops. In addition, plants are subject to various biotic and abiotic stresses that limit their growth and productivity. The potential of the plant-associated microbial community to overcome biotic and abiotic stresses in plants can be interlinked to mitigate the current challenges in food security. For this, there is an urgent need to bring microbial innovations into practice.

Microbiome engineering is an emerging biotechnological strategy to improve the functional capabilities of native microbial species under biotic and abiotic stresses. It is a win-win strategy where both humans and the environment are benefited by improving crop yield and soil health. Conditioning the soil using suitable amendments, cultivating microbe-recruiting plant cultivars (host-dependent microbiome engineering), and inoculating synthetic microbial communities are microbiome approaches which improve plant health under stress conditions by increasing the functionally active and diverse microbial communities.

Traditional soil organic formulations such as compost, organic residues, organic waste, and peat can be used to support the growth and activation of beneficial soil microbes. Plant-oriented signaling molecules such as salicylic acid and metabolites in root exudates have a strong effect on the dynamics and the composition of the microbiome. It was suggested that these microbe-stimulating compounds can be artificially modulated and can be used as the soil conditioners.

Artificial microbial consortia (AMC) can also be used to improve the multiple functions relevant to crop plant growth and development. This strategy is the best alternative to solve the drawbacks of traditional bio fertilizers. Plant growth promoting rhizobacteria (PGPR) and AM fungi can also be artificially inoculated into soils to alter the structure of microbial communities. For example, inoculating chili plant roots with Bacillus amyloliquefaciens, Acinetobacter sp. and Bacillus velezensis have promoted the growth of chili plants and have shown the disease suppressive ability against Phytophthora capsica. Genetic engineering is also leading to the development of host-specific bio fertilizers.

References
Noman, M.; Ahmed, T.; Ijaz, U.; Shahid, M.; Azizullah; Li, D.; Manzoor, I.; Song, F. Plant–Microbiome Crosstalk: Dawning from Composition and Assembly of Microbial Community to Improvement of Disease Resilience in Plants. Int. J. Mol. Sci. 2021, 22, 6852. https://doi.org/10.3390/ijms22136852

Albright, M.B.N., Louca, S., Winkler, D.E. et al. Solutions in microbiome engineering: prioritizing barriers to organism establishment. ISME J 16, 331–338 (2022). https://doi.org/10.1038/s41396-021-01088-5

Image courtesy
Featured image – https://www.farmersnational.com/Blog/Agricultural_Real_Estate/What_is_the_Best_Auction_Method_for_Selling_Land/

Figure 1 – Noman, M.; Ahmed, T.; Ijaz, U.; Shahid, M.; Azizullah; Li, D.; Manzoor, I.; Song, F. Plant–Microbiome Crosstalk: Dawning from Composition and Assembly of Microbial Community to Improvement of Disease Resilience in Plants. Int. J. Mol. Sci. 2021, 22, 6852. https://doi.org/10.3390/ijms22136852

Biotechnology is the technology that utilizes biological systems, living organisms or parts of these to develop or create different products. The application of microbes in sustainable agriculture and the environment is a rapidly growing segment in the novel world. Increasing food demand poses a great challenge to the traditional agriculture system. While the development of biotechnology applications began in 6000 BC., the development of genetic tools and cellular engineering was initiated in 1970. Genetically modified (GM) crops that are resistant to many pathogens and weeds have contributed to the increase of high yields in agriculture.

Biofertilizers are the preparation of live or latent cells of efficient strains of microorganisms used for application to accelerate the process of plant growth and development. They can add 20-200 Kg N/ha per year under optimum soil conditions and thereby increase the total crop yield by 15-25%. Rhizobium BGA, Azotobacter sp., Gluconacetobacter spp. stimulate the production of growth-promoting substances like Vitamin-B complex, Indole acetic acid (IAA) and Gibberellic acid. Phosphate solubilizing/mobilizing biofertilizers solubilize/mobilize about 30-50Kg P₂O₅/ha. Azotobacter inoculants applied to non-legume plants promote seed germination and the initial vigor of plants. Phosphate ions (PO₄^3-) mobilize the Mycorrhiza (VAM fungi) and enhance the uptake of P, Zn, S & water leading to uniform crop growth & enhancing resistance to disease & hardiness of transplant stock. They act as antagonists and suppress the incidence of soil-borne pathogens thus helping in the control of diseases. Biofertilizers improve the physical properties, tilth, productivity and health of the soil. Nostoc, Anabaena and Scytonema have reclaimed the alkaline soils. Cellulolytic and ligninolytic microorganisms enhance the degradation/decomposition of organic matter in the soil.

Biopesticides are microbes possessing invasive genes that can attack the defense genes of weeds by killing them. Endospores of the Bacillus thuringiensis (Bt) are used as an organic pesticide because some strains produce crystals in the endospores that are toxic to insects when they consume endospores. Controversial crop plants are genetically modified with the Bt toxins genes to develop resistance to pests. Bioherbicides can persist for a long time in the environment which can exist for the upcoming growing season and affect target pathogens only. Seed coated with inoculants can be developed to protect the plants during their critical seedling stage.

Bioinsecticides are naturally-occurring substances from different sources that control insect pests. They are low toxicity to non-target microorganisms, easily degradable, highly effective in small quantities and effect on target pests only. The bioinsecticides contain microbes such as Beauveria bassiana, Metarhizium anisopliae or brunneum and Isaria fumosorosea contact with pests, affect the nervous and muscular system, paralyzing and eventually killing the insects and mites.

Bioremediation is the process that makes use of microorganisms to eliminate pollutants from soil. Microorganisms can sequestrate toxic metals by cell wall components, alternating biochemical pathways to block metal uptake, converting metals into innocuous forms by enzymes, enhancing the mobility by siderophores and reducing the availability of heavy metals. Desulfovibrio desulfuricans convert sulphate to hydrogen sulphate that reacts with heavy metals to convert an insoluble form of metal sulphides. The genetically modified strain of P. fluroscences HK 44 is able to sense pollution, signaling through bioluminescence.

References

Binte Mostafiz, S., Rahman, M., Binte, S., Rahman, M. and Rahman, M. (2012). Biotechnology: Role of Microbes in Sustainable Agriculture and Environmental Health Quantification and analysis of Somatic embryogenesis receptor like kinase gene expression on Malaysian Indica rice View project Low carbon pathways_GUP_UTM JB View project The Internet Journal of Microbiology Biotechnology: Role of Microbes in Sustainable Agriculture and Environmental Health. Agriculture And Environmental Health. The Internet Journal of Microbiology, [online] 10(1). doi:10.5580/2b91.

Dhir, B. (2017). Biofertilizers and Biopesticides: Eco-friendly Biological Agents. Advances in Environmental Biotechnology, pp.167–188. doi:10.1007/978-981-10-4041-2_10.

Berg, G. (2009). Plant–microbe interactions promoting plant growth and health: perspectives for controlled use of microorganisms in agriculture. Applied Microbiology and Biotechnology, 84(1), pp.11–18. doi:10.1007/s00253-009-2092-7.

Image courtesy

Featured image – https://www.peptechbio.com/blog-biofertilizers/
Figure 1 – https://www.sciencedirect.com/science/article/pii/B9780128223581000092

Global food production has increased by many folds as compared to the past, but still, the pace of agricultural productivity is not adequate for a rapidly increasing population. Presently, chemical fertilizers used for crop yield improvements are not compatible because of their environmental hazards and cost. Indiscriminate use of synthetic fertilizers has led to pollution and contamination of soil and water basins. This has resulted in the soil being deprived of essential plant nutrients and organic matter. It has led to the depletion of beneficial microorganisms and insects, indirectly reducing soil fertility and making crops more prone to diseases. The increasing cost of fertilizers would be unaffordable to small and marginal farmers, thus intensifying the depleting levels of soil fertility due to the widening gap between nutrient removal and supplies. In the present scenario, there has been a real resurgence of environmental-friendly, sustainable agricultural products. Biofertilizers are formulations that contain living microorganisms that have the ability to colonize crop roots and promote growth by improving nutrient availability and acquisition.

Classification of Biofertilizers
Several microorganisms and their interactions with crop plants are being used to create biofertilizers. They can be grouped in different ways based on their nature and function.

Rhizobium: Rhizobium is a soil habitat bacterium, which colonizes legume roots and fixes atmospheric nitrogen symbiotically. Morphology and physiology differ from free-living conditions to nodule bacteroids. They are the most efficient biofertilizers as per the quantity of nitrogen fixed. They have seven genera and are highly specific for forming nodules in legumes, referred to as cross inoculation.

Azotobacter: Among various Azotobacter species, A. chroococcum happens to be the dominant inhabitant in arable soils capable of fixing N2 (2-15 mg N2 fixed /g of carbon source) in culture media. The bacterium produces abundant slime, which helps in soil aggregation. The numbers of A. chroococcum in Indian soils rarely exceeds 105/g soil due to a lack of organic matter and the presence of antagonistic microorganisms in soil.

Azospirillum: Azospirillum lipoferum and A. brasilense are primary inhabitants of the soil, the rhizosphere, and intercellular spaces of the root cortex of graminaceous plants. They develop associative symbiotic relationships with graminaceous plants. Apart from nitrogen fixation, growth promoting substance production (IAA), disease resistance, and drought tolerance are some of the additional benefits of inoculation with Azospirillum.

Cyanobacteria: Both free-living as well as symbiotic cyanobacteria (blue green algae) have been harnessed in rice cultivation.

Azolla is a free-floating water fern that floats in water and fixes atmospheric nitrogen in association with the nitrogen-fixing blue green alga Anabaena azollae. Azolla can be used either as an alternate nitrogen source or as a supplement to commercial nitrogen fertilizers. Azolla is used as a biofertilizer for wetland rice and it is known to contribute 40–60 kg N/ha per rice crop.

Phosphate solubilizing microorganisms (PSM): Several soil bacteria and fungi, notably species of Pseudomonas, Bacillus, Penicillium, Aspergillus, etc., secrete organic acids and lower the pH in their vicinity to bring about the dissolution of bound phosphates in soil. Increased yields of wheat and potatoes were demonstrated due to inoculation of peat-based cultures of Bacillus polymyxa and Pseudomonas striata.

AM fungi: The transfer of nutrients, mainly phosphorus, and also zinc and sulphur from the soil milleu to the cells of the root cortex is mediated by intracellular obligate fungal endosymbionts of the genera Glomus, Gigaspora, Acaulospora, Sclerocysts, and Endogone, which possess vesicles for storage of nutrients and arbuscules for funneling these nutrients into the root system. By far, the commonest genus appears to be Glomus, which has several species distributed throughout the soil.

Silicate solubilizing bacteria (SSB): Microorganisms are capable of degrading silicates and aluminum silicates. Several organic acids are produced during the metabolism of microbes, and these have a dual role in silicate weathering. They supply H+ ions to the medium and promote hydrolysis. Also, they promote the removal of and retention of organic acids like citric, oxalic acid, keto acids, and hydroxy carbolic acids, in the medium in a dissolved state.

Plant growth promoting rhizobacteria (PGPR): The group of bacteria that colonize roots or rhizosphere soil and are beneficial to crops is referred to as plant growth promoting rhizobacteria (PGPR). The PGPR inoculants promote growth through suppression of plant disease (termed Bioprotectants), improved nutrient acquisition (termed Biofertilizers), or phytohormone production (termed Biostimulants). Species of Pseudomonas and Bacillus can produce as yet not well characterized phytohormones or growth regulators that cause crops to have greater numbers of fine roots, which have the effect of increasing the absorptive surface of plant roots for uptake of water and nutrients. These PGPR are referred to as Biostimulants, and the phytohormones they produce include indole-acetic acid, cytokinins, gibberellins, and inhibitors of ethylene production.

The formulation of biofertilizers is a crucial multistep process that includes the mixing of a suitable carrier with an inoculant, providing optimal conditions during storage, packaging, and dispatch, and ensuring survival and establishment after introduction into soil.

Methods of Application of Biofertilizers
Seed Treatment: 200 g of biofertilizer is suspended in 300-400 mL of water and mixed gently with 10 kg of seeds using an adhesive like gum acacia, jiggery solution, etc. The seeds are then spread on a clean sheet or cloth under shade to dry and can be used immediately for sowing.

Seedling Root Dip: This method is used for transplanted crops. For rice crops, a bed is made in the field and filled with water. Recommended fertilizers are mixed in this water and the roots of seedlings are dipped for 8–10 h and transplanted.

Soil Treatment: 4 kg each of the recommended biofertilizers is mixed in 200 kg of compost and kept overnight. This mixture is incorporated in the soil at the time of sowing or planting.

Advantages of Using Biofertilizers
Some of the advantages associated with biofertilizers include:

• They are eco-friendly as well as cost-effective.
• Their use leads to soil enrichment, and the quality of the soil improves with time.
• Though they do not show immediate results, the results shown over time are spectacular.
• These fertilizers harness atmospheric nitrogen and make it directly available to the plants.
• They increase the phosphorus content of the soil by solubilizing and releasing unavailable phosphorus.
• Biofertilizers improve root proliferation due to the release of growth-promoting hormones.
• Microorganisms convert complex nutrients into simple nutrients for the availability of the plants.
• Biofertilizer contains microorganisms which promote the adequate supply of nutrients to the host plants and ensure their proper development of growth and regulation in their physiology.
• They help in increasing the crop yield by 10–25%.
• Biofertilizers can also protect plants from soil-borne diseases to a certain degree.

Constraints in Biofertilizer Technology
Despite the fact that biofertilizer technology is a low-cost, environmentally friendly technology, several constraints limit its application or implementation. The constraints may be:

• Technological constraints like the unavailability of good quality carrier material and a lack of qualified technical personnel in production units.
• Infrastructural constraints like lack of essential equipment, power supply, etc.
• Financial constraints like non-availability of sufficient funds and problems in getting bank loans.
• Environmental constraints like seasonal demand for biofertilizers, simultaneous cropping operations, and a short span of sowing/planting in a particular locality, etc.
• Human resource and quality constraints, such as a lack of technically qualified personnel in production units and a lack of appropriate production technique training,
• Unawareness of the benefits of the technology due to problems in adoption of the technology by the farmers due to different methods of inoculation, no visual difference in the crop growth immediately as that of inorganic fertilizers.

Application of biological fertilizers is thought to be a key element in maintaining soil fertility and crop productivity at a sufficiently high level, which is indispensable to achieve the sustainability of farming. Biofertilizers may also help mitigate pitfalls arising from the growing demand of the global population for food and from the widespread chemicalization of agroecosystems. The changing approach to agricultural practices makes biofertilizers a vital part of modern-day crop production and emphasizes the significance of biological inoculants in forthcoming years.

References
DebmalyaDasguptaa,KulbhushanKumarbRashi,MiglanibRojita,MishracAmrita Kumari,PandadSatpal SinghBishtb.(2021). Microbial biofertilizers: Recent trends and future outlook:Toward the establishment of Microbial biofertilizers: Recent trends and future outlook.

S. Kannaiyan, Cyanobacterial biofertilizer technology for rice crops. In: Algal biotechnology (Trivedi, P.C. Ed.). Pointer publishers, Jaipur, India.2001. Rakesh Kumar, Narendra Kumawat,Yogesh Kumar Sahu.(2017). Role of Biofertilizers in Agriculture.

Image courtesy
Featured image – https://Anuvia aims to have its biofertilizer on 20m farm acres by 2025 (agfundernews.com)
Figure 1 – https://www.aimpress.com/article/id/371

Modernized agricultural methods play a significant role in meeting the food demands of a growing world population, which has also led to an increasing dependence on chemical fertilizers and pesticides. The term “chemical fertilizer” refers to any number of synthetic compound substances created specifically to increase crop yield and composed of known quantities of nitrogen, phosphorus, and potassium, and their exploitation causes air and groundwater pollution by eutrophication of water bodies. Because of this, recent attention has been given to developing an environmentally friendly bio fertilizer.

The new trend in agricultural production is the use of biological-based organic fertilizers as an alternative to agro-chemicals. This means that soil fertilization relies on organic inputs to improve nutrient supply and conserve field management. Organic farming is one such strategy that not only ensures food safety but also adds to the biodiversity of the soil. The additional advantages of bio fertilizers include longer shelf life, causing no adverse effects to the ecosystem. Bio fertilizer is made up of free living bacteria that promote plant growth, increase productivity through root strengthening, and help to reduce the amount of synthetic fertilizer used on crops.

Organic farming is mostly dependent on the natural microflora of the soil, which constitutes all kinds of useful bacteria and fungi, including the arbuscular mycorrhiza fungi (AMF) and plant growth-promoting rhizobacteria (PGPR). Through nitrogen fixation, phosphate and potassium solubilization or mineralization, the release of plant growth regulating substances, the production of antibiotics, and the biodegradation of organic matter in the soil, biofertilizers keep the soil environment rich in all types of micro- and macronutrients.

When bio fertilizers are applied as a coating for seeds or directly as soil inoculants, the microbes present multiply and participate in nutrient cycling, boosting crop productivity.

In general, 60% to 90% of the total applied fertilizer is lost, and the remaining 10% to 40% is taken up by plants in the traditional use of chemical fertilizer. In this regard, microbial inoculants have paramount significance in integrated nutrient management systems to sustain agricultural productivity and a healthy environment. The PGPR or co-inoculants of PGPR and AMF can increase the nutrient use efficiency of fertilizers.

The rhizosphere, which is the narrow zone of soil surrounding plant roots, can comprise up to 1011 microbial cells per gram of root and over 30,000 prokaryotic species. There are microbial strains providing numerous services to crop plants, like organic matter decomposition, nutrient acquisition, water absorption, nutrient recycling, weed control, and bio-control. Rhizosphere microbial communities are an alternative to chemical fertilizers and have become a subject of great interest in sustainable agriculture and bio-safety programs.

A major focus in the coming decades will be on safe and environmentally friendly methods of sustainable crop production by utilizing beneficial microorganisms.Such microorganisms, in general, consist of diverse naturally occurring microbes whose inoculation into the soil ecosystem advances soil physicochemical properties, soil microbe biodiversity, soil health, plant growth and development, and crop productivity. The agriculturally useful microbial populations include plant growth promoting rhizobacteria, N2-fixing cyanobacteria, mycorrhiza, plant disease suppressive beneficial bacteria, stress tolerance endophytes, and bio-degrading microbes.

These biofertilizers are a supplementary component to soil and crop management traditions. Azotobacter, Azospirillum, Rhizobium, cyanobacteria, phosphorus and potassium solubilising microorganisms, and mycorrhizae are some of the PGPRs that were found to increase in the soil under no tillage or minimum tillage treatment. Efficient strains of Azotobacter, Azospirillum, Phosphobacter, and Rhizobacter can provide a significant amount of nitrogen to plants and increase the plant height, number of leaves, stem diameter, percentage of seed filling, and seed dry weight. Similarly, in rice, the addition of Azotobacter, Azospirillum, and Rhizobium promotes the physiology and improves the root morphology.

References
Abbaszadeh-Dahaji, P., Masalehi, F., and Akhgar, A. (2020). Improved growth and nutrition of sorghum (Sorghum bicolor) plants in a low-fertility calcareous soil treated with plant growth–promoting rhizobacteria and Fe-EDTA. J. Soil Sci. Plant Nutr.

Agnolucci, M., Avio, L., Pepe, A., Turrini, A., Cristani, C., Bonini, P., et al. (2019). Bacteria associated with a commercial mycorrhizal inoculum: community composition and multifunctional activity as assessed by illumina sequencing and culture-dependent tools.

Ahmed, B., Midrarullah, and Sajjad Mirza, M. (2013). Effects of inoculation with plant growth promoting rhizobacteria (PGPRs) on different growth parameters of cold area rice variety, Fakre malakand. Afr. J. Microbiol.

Ahmed, E., and Holmström, S. J. M. (2014). Siderophores in environmental research: roles and applications. Microb. Biotechnol.

Alori, E. T., Glick, B. R., and Babalola, O. O. (2017). Microbial phosphorus solubilization and its potential for use in sustainable agriculture.

Image courtesy
Featured image – https://biomassmagazine.com/articles/19167/unlocking-biofertilizer-as-additional-revenue-source

The world has encountered a food and energy crisis due to accelerated population growth and the depletion of finite fossil fuels. Currently, fossil fuel resources are not regarded as sustainable and their continued consumption is raising severe ecological, economic and environmental questions. Microalgae have recently attracted considerable interest worldwide due to their extensive application potential in the renewable energy, biopharmaceutical, and nutraceutical industries. Actually, microalgae are biorefineries where biomass is converted into a variety of products like biofuels, food and feed supplements, fertilizer, pharmaceuticals, and other products.
Microalgae are ubiquitous, unicellular or simple multicellular, prokaryotic or eukaryotic, photosynthetic microscopic organisms. Even though there are more than 50,000 species exist, only a limited number, of around 30,000, have been studied and analyzed. They may be autotrophic, heterotrophic, or both. Prokaryotes like Cyanobacteria and eukaryotes including Green algae and Diatoms are some examples for microalgae. Dense accumulations of microscopic algal or cyanobacterial cells in water bodies resulting from high nutrient contents are known as algal blooms.
Microalgae are the missing solution to fight climate change mainly occurred due to anthropogenic CO2 and other greenhouse gas emissions. Biological CO2 fixation will be the economical and environmentally viable technology of the future. Compared to terrestrial plants, microalgae have faster growth rates and their CO2 fixation efficiency is also between 10 and 50 times higher. When using microalgae for CO2 mitigation, no additional CO2 is created, while nutrient utilization is achieved in a continuous fashion leading to the production of biofuels and other secondary metabolites. Therefore, it can be coupled with biofuel production and wastewater treatment. Routinely used microalgal and cyanobacterial species for CO2 mitigation are Anabaena sp., Chlamydomonas reinhardtii, Chlorella sp., Scenedesmus sp., Spirulina sp., and Euglena sp.

Microalgae biomass is considered to be a suitable feedstock for biofuel production including biodiesel, butanol, bioethanol, biogas, bio-oil, and jet fuel. Microalgal biofuels overcome a number of the shortcomings of first- and second-generation biofuels, as they produce considerably higher biomass yields (20-30 times) with lower resource inputs than other feedstocks and they are able to grow under conditions unsuitable for crop plants. Bioelectricity also can be generated from microalgae. Algal Fuel Cells are bioelectric devices that use photosynthetic organisms to turn light and biochemical energy into electrical energy.
Microalgae can be used to treat industrial, agricultural and domestic wastewater. They can remove the pollutants simultaneously while utilizing solar energy for their growth and they are able to grow in the arid environment and highly saline water. Cultivation of microalgae in wastewater does not require oxygen supply. Harvested biomass also can be used to produce high-value pigments, fish and animal feed, biofertilizers, and bioplastics. Microalgae can be used in agriculture as biofertilizers, a promising strategy to reduce dependency on agrochemicals, biostimulants, biocontrol agents, soil conditioners, and organic fertilizers.
Microalgae possess high nutritional value. They contain high concentrations of proteins, lipids, polyunsaturated fatty acids, and bioactive carbohydrates such as polysaccharides. Also, they are especially valuable for their high content of essential omega-3 fatty acids. So, they are used as food and feed additives and supplements. Also, they contain antioxidants including pigments such as carotenes, chlorophylls, and phycobiliproteins important for health and cosmetic applications. Spirulina, Chlorella, Dunaliella, and Haematococcus are some microalgae widely used as food supplements, feed, and nutraceuticals. There are microalgal bio-based materials such as microalgal bioplastics and algae carbon fiber.
So, do you still think of microalgae as pond scum? How will you embrace algae in the future?

References:
Khan, M.I., Shin, J.H. & Kim, J.D. The promising future of microalgae: current status, challenges, and optimization of a sustainable and renewable industry for biofuels, feed, and other products. Microb Cell Fact 17, 36 (2018). https://doi.org/10.1186/s12934-018-0879-x

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Featured image:
https://www.wur.nl/upload_mm/d/b/3/81bc4b99-4c6f-4e2f-b1ef-78e0b0998801_algen_micro_shutterstock_101601940_1000_2c1552a9_750x400.jpg
Figure 1:
https://onlinelibrary.wiley.com/cms/asset/73d4a44f-b9b4-499c-a3f5-137f689aae2a/elsc1269-fig-0002-m.jpg
Figure 2:
https://www.israel21c.org/wp-content/uploads/2020/05/Picture6-1-768×363.jpg

The global population is gradually increasing over time. In 2050, it is estimated that the world population will exceed 10 billion people. Since the existing agricultural systems, land, and natural resources are already maximally exploited, the problem lies in how to feed the increasing population. Climatic changes, environmental pollution, and urbanization have become a great challenge to future agricultural processes. The global temperature rising, extreme weather, changing climatic patterns and loss of arable lands have driven the world to investigate more sustainable pathways to fulfill the global needs in an eco-friendly manner.

The introduction of “Algae Biotechnology'' is the newest trend that allows us to overcome these problems in a sustainable and eco-friendly manner. Algal biotechnology is a technology developed using algae. This can be divided into microalgae and macroalgae technology. Here I mainly focus on the applications of microalgae technology. Photosynthetic microalgae are one of the most abandoned communities in the world that can be identified in a vast range of habitats. According to the statistics, more than 200,000 species with numerous ecological adaptations are available in the world.

These phototrophic algae have the advantage of using sunlight to fix atmospheric carbon and reduce their reliance on sugar for fermentation. Many species of microalgae can grow rapidly even under extreme conditions. When thinking about large-scale cultivations, unlike plants, the algae can be cultured in the ponds or photobioreactors by using non-arable lands with less freshwater or even with seawater or wastewater.

The photosynthetic efficiency of the algae is very high compared to crop plants. For example, we can compare algae with sugarcane. One of the most productive plants on the planet is sugarcane, and it can accumulate up to 25 tons of biomass per acre per year. However about 80 percent of that biomass is cellulose, which is not very useful in biofuel production. Algae can accumulate at least twice that biomass, up to 50 tons per acre per year, and that’ll be beneficial. So, we can consider this as a great source to open new chances in order to fulfill a vast number of global needs. Yet most of the people in the world are not aware of the potential of this great source. Therefore the implementation of these industrial applications is relatively low at the present.
Now we will focus on some applications of microalgae biotechnology. Algae biotechnology can be used in producing food and nutraceuticals. Microalgae can act as a source of nutrients, minerals, trace elements, and other bioactive compounds. These are rich sources of bulk protein, carbohydrates, and lipids. With less recourse and effort, by implementing these techniques high-quality protein for human and animal consumption can be produced.

The secondary metabolites obtained from algae can be used to produce expensive pharmaceuticals and pigments for the apparel industry. Another best application of algae biotechnology is the production of biopolymers, bioplastics, and bulk chemicals. Now our planet is almost covered in plastic trash. Plastic was only invented a little more than 60 years ago and yet today there are already 17 trillion pounds of plastic on this planet. This may lead to huge environmental damage. Therefore, the alternatives for petrochemical-based plastics sources are in high demand. Algae have the potential to be an economically viable feedstock for bioplastics production because these biomass compounds such as starch, carbohydrates, and lipids can be converted into plastics. So, in this way, we can produce biodegradable plastics and polymers efficiently at a low cost. Biomass-derived chemicals 5-hydroxymethylfurfural (5-HMF), levulinic acid, furfurals, sugar alcohols, lactic acid, succinic acid, and phenols, are known as platform chemicals. These are used for producing a variety of important chemicals on an industrial scale. Bio-based bulk chemicals are a good substituent for fossil oil-based bulk chemicals.

Moreover, the presence of emerging contaminants in the environment is a potential risk to ecosystems and human health at environmentally relevant concentrations. Microalgae have the potential to detoxify organic and inorganic pollutants. Coupling of nutrient and emerging contaminants removal by microalgae has the potential to provide more cost-effective and efficient wastewater treatment while meeting both environmental and human health protection goals.

So, algae biotechnology is a great opportunity to fulfill essential human needs while protecting the ecosystems and recovering the environmental issues. I realize it as a key to open the door that blocks the way to the green world. In my opinion, we should pay more attention to these types of alternatives to meet our goals of sustainability.

References
Michele Fabris, Raffaela M. Abbriano,Mathieu Pernice, Donna L. Sutherland, Audrey S. Commault, Christopher C. Hall1, Leen Labeeuw1, Janice I. McCauley, Unnikrishnan Kuzhiuparambil, Parijat Ray, Tim Kahlke, Peter J. Ralph. (2020). Emerging Technologies in Algal Biotechnology: Toward the Establishment of a Sustainable, Algae-Based Bioeconomy. Frontiers In Plant Science

https://www.frontiersin.org/articles/10.3389/fpls.2020.00279/full

Image Courtesy:
Featured image:
https://cordis.europa.eu/article/id/415760-lab-grown-algae-the-future-of-food
Figure 1:

https://www.chemistryviews.org/details/ezine/8639701/Microalgae__Underestimated_All-Rounders.html
Figure 2:

https://www.researchgate.net/publication/210202714_Application_of_computational_fluid_dynamics_for_modeling_and_designing_photobioreactors_for_microalgae_production_A_review

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.

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.

‘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.

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

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.

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/

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.

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.

References

1. https://pubs.rsc.org/en/content/articlehtml/2020/ra/d0ra03514a
2. https://www.frontiersin.org/articles/10.3389/fchem.2018.00052/full
3. https://www.longdom.org/open-access/pigments-and-pathogenesis-2161-1068-4-168.pdf
4. https://www.researchgate.net/publication/230186371_Carotenoids_and_abscisic_acid_ABA_biosynthesis_in_higher_plants
5. https://scialert.net/fulltext/?doi=jas.2011.2406.2410
6. https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1399-3054.1991.tb00100.x
7. https://link.springer.com/chapter/10.1007/978-3-319-90698-0_3
8. https://en.wikipedia.org/wiki/Biological_pigment
9. https://fashion-history.lovetoknow.com/fabrics-fibers/acrylic-modacrylic-fibers
10. https://www.fibre2fashion.com/industry-article/3333/dyeing-of-textile-fibre-using-marigold-flower

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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.

References

https://www.nationalgeographic.com/science/2020/08/microplastics-in-virtually-every-crevice-on-earth/

https://www.theguardian.com/environment/2019/aug/14/microplastics-found-at-profuse-levels-in-snow-from-arctic-to-alps-contamination

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

https://doi.org/10.1016/B978-0-12-819001-2.00022-X

https://aem.asm.org/content/77/17/6076

Image courtesy

https://www.sciencenewsforstudents.org/article/help-for-a-world-drowning-in-microplastics

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