Microorganism, the omnipresent micro-sized creatures are contributing their services in environment safekeeping, augmenting and making it safe for the survival of human civilization. Microbial processes are associated with production of healthier food supplements, nutrient cycling, biodegradation, climate change, production of environment friendly alternatives to non-degrading synthetic materials and bioremediation of toxic wastes. Various microbial species contribute in production of biofuels or bioplastics as environmental-friendly, less-polluting alternatives. Other species are contributing in bioremediation processes to reduce the toxic substances.

Key words: Microbes, Microbial processes, Biofuels,   Nutrient Cycling

Introduction

Since time immemorial, microbial processes are associated with our house hold activities like making fermented food. Then nobody knew why & how a raw food material changed into a useful food product.  Now we deal with many different kinds of microorganisms for both culinary & other domestic purpose. Microbes are very useful and also harmful to humans and to the environment as well. They play crucial roles in nutrient cycling, biodegradation, climate change, the cause and control of the disease. They are widely employed in many ways like manufacturing biofuels, cleaning up pollution, producing or processing of drinks and food-products. Our world is on the brink of a revolution, accelerated by microorganisms. Thanks to microorganisms, we have products which have capacitated us to lead healthier life and make great progress.(1,2) Nowadays microbiology offers plethora of opportunities for human welfare and developing an improved environment.

Some aspects are as follows:

Bioplastic:Plastic, the biggest threat for environment & humans finds enormous application in context to food related items from packaging, crockery, cutlery, pots, bowls, to straws. Bioplastic is the emerging solution. Bioplastics are the plastics that are made from renewable resources and able to break down naturally. These innovative plastic materials are produced from renewable biomass sources by enabling specific microbial activities on material such as vegetable fats and oils, corn starch, straw, woodchips, sawdust, recycled food waste, etc. (3,4).Bioplastic can also be made from agricultural by-products and also from used plastics by using microorganisms. Bioplastics are usually derived from sugar derivatives, including starch, cellulose, and lactic acid. Poly-(3-)hydroxybutyrate (PHB) and poly-(3-)hydroxyalkanoate (PHB) are the two chief classes of bioplastics. PHB is synthesised by Bacillus megaterium and Ralstonia eutropha whereas, PHAs are chiefly harvested from Pseudomonas oleovorans , P. putida and Alcaligenes eutrophus. Various other chief contributing microbial agents include Chromatium vinosum, Brevibacterium epidermidis, Clostridium kluyveri,  Rhizobium (Cicer) sp.,  Thiocystis violacea, Thiocapsa pfennigii and Synechocystis sp.(5,6)  

Biofuel: Biofuel, is any fuel that is derived from biomass i.e. plant or algae material or animal waste. It is considered to be a source of renewable energy, unlike fossil fuels such as petroleum, coal, and natural gas. Biofuels include bioethanol (often made from corn and sugarcane), biodiesel (sourced from vegetable oils and liquid animal fats), green diesel and biogas (methane derived from animal manure and other digested organic material as microbial metabolic by-product)(7) . Green diesel can b obtained by plant products of Jatropha curcas, Soybean and oil palm, seeds of the tropical plants Anacardium occidentale L (cashew), Cocos nucifera (coconut palm) and Gossypium hirsutum (upland cotton) by microbial activities of Tetradesmus obliquus, Botryococcus braunii, Spirulina, Chlorella vulgaris, Spirulina maxima, Nannochloropsis sp., Neochloris oleoabundans, Scenedesmus obliquus and Dunaliella tertiolecta.  Similarly, Methanobacterium, Methanoculleus , Methanobrevibacter, Methanolinea and Methanosaeta  aid in biogas production from ruminant excreta and other digested organic material as a metabolic by-product. Microbes also find application in environment safekeeping & are used to produce bio-ethanol which is produced from lingocellulose, cellulose and hemicellulose (constituents of plant cell wall) by Klebisella oxytoca and Saccharomyces cerevisiae.(8,9). The enzymes for their breakdown are cellulose, lignase etc and are found in various microbial species. These enzymes are extracted from Trichoderma sp.,  Aspergillus terreus, Cyathus stercoreus, Lentinus squarrosulus, Lentinus edodes, Pleurotus sp., Penicillium camemberti and various other microbial sources.(10)

Bioremediation

Bioremediation is another environment favoring branch of microbiology that employs the use of living organisms, like algae and bacteria, in the removal of contaminants, pollutants, and toxins from soil, water, and other environments. (11)Bioremediation relies on stimulating the growth of certain microbes that utilize contaminants like oil, solvents, and pesticides for sources of food and energy. These microbes convert contaminants into small amounts of water, as well as harmless gases like carbon dioxide. (12)  It finds application in cleaning up oil spills or contaminated groundwater. Bioremediation may be done "in situ"–at the site of the contamination–or "ex situ"–away from the site.  It requires a combination of the right temperature, nutrients, and foods. Bioremediation is less expensive and more sustainable than other remediation alternatives(13). Biological treatment is a similar approach used to treat wastes including wastewater, industrial waste and solid waste. (14,15). Some examples of bioremediation related technologiesinclude phytoremediation, mycoremediation, bioventing, bioleaching, landfarming, bioreactor,composting, bioaugmentation, rhizofiltration, and biostimulation. (16). Common microbial agents for bioremediation are Pseudomonas putida, Dechloromonas aromatica, Deinococcus radiodurans, Methylibium petroleiphilum, Alcanivorax borkumensis and Phanerochaete chrysosporium.( 17, 18).

Probiotics:

Probiotics are live microorganisms that when consumed, provides health benefits and improves or restores the gut flora. The most important medicinal properties displayed by microbial strains used as probiotic  include: resistance to gastric acidity, bile acid resistance, adherence to mucus and human epithelial cells and cell lines, antimicrobial activity against potentially pathogenic bacteria or fungi, ability to reduce pathogen adhesion to surfaces, bile salt hydrolase activity, enhancing viability of probiotics. (19). Health benefits have mainly been demonstrated for specific probiotic strains like Lactobacillus, Bifidobacterium, Saccharomyces, Enterococcus, Streptococcus, Pediococcus, Leuconostoc, Bacillus, Escherichia coli.  Lactobacilli sp. are used for the production of yogurt, cheese, sauerkraut, pickles, sourdough, wine and other fermented products.

They are a major part of the lactic acid bacteria (LAB) group, which also includes Lactobacillus, Lactococcus, Enterococcus, Oenococcus, Pediococcus, Streptococcus and Leuconostoc species,  which can convert hexose sugars to lactic acid thus producing an acid environment which inhibits the growth of several species of harmful bacteria  Similarly, several strains of Bifidobacteria are considered as important probiotics including: Bifidobacterium infantis, B. adolescentis, B. animalis subsp animalis, B. animalis subsp lactis, B. bifidum, B. longum, B. breve.  Saccharomyces bayanus (used for making wine). Saccharomyces boulardii also find application in medicine as a probiotic.(20,21,22).

Conclusion

The microorganism is very useful for mankind, it can be used for essential products and production. Nowadays microorganisms use in every field to prepare different agriculture, food, and medical product. 

References

1. Abatenh, E., Gizaw, B., Tsegaye , Z., & Tefera, G. (2018). Microbial Function on Climate Change - A Review. Environment Pollution and Climate Change, 02(01). doi:10.4172/2573-458x.1000147 

2. Chen, Y., Cheng, H., Yang, Y., & Yeh, M. K. (2017). Biotechnologies Applied in Biomedical Vaccines. Vaccines. doi:10.5772/intechopen.69547 

3. Pramanik, P., Mina, U., & Sharma, N. (2015) Bioplastic: Sustainable Green Plastic.  SCIENCE REPORTER, DECEMBER Page no-26-27 2015

4. Paula, F. C. de, Paula, C. B. C. de, & Contiero, J. (2018). Prospective Biodegradable Plastics from Biomass Conversion Processes. Biofuels - State of Development. doi:10.5772/intechopen.75111 

5. Irorere, V. U., Bagheriasl, S., Blevins, M., Kwiecie?, I., Stamboulis, A., & Radecka, I. (2014). Electrospun Fibres of Polyhydroxybutyrate Synthesized byRalstonia eutrophafrom Different Carbon Sources. International Journal of Polymer Science, 2014, 1–11. doi:10.1155/2014/705359 

6. Lin, Y.-Y., & Chen, P. T. (2017). Development of polyhydroxybutyrate biosynthesis in Bacillus subtilis with combination of PHB-associated genes derived from Ralstonia eutropha and Bacillus megaterium. Journal of the Taiwan Institute of Chemical Engineers, 79, 110–115. doi:10.1016/j.jtice.2017.02.030 

7. Balan, V. (2014). Current Challenges in Commercially Producing Biofuels from Lignocellulosic Biomass. ISRN Biotechnology, 2014, 1–31. doi:10.1155/2014/463074 

8. Kang, Q., Appels, L., Tan, T., & Dewil, R. (2014). Bioethanol from Lignocellulosic Biomass: Current Findings Determine Research Priorities. The Scientific World Journal, 2014, 1–13. doi:10.1155/2014/298153 

9. Tesfaw, A., & Assefa, F. (2014). Current Trends in Bioethanol Production by Saccharomyces cerevisiae: Substrate, Inhibitor Reduction, Growth Variables, Coculture, and Immobilization. International Scholarly Research Notices, 2014, 1–11. doi:10.1155/2014/532852 

10. Tyagi, S., Lee, K.-J., Mulla, S. I., Garg, N., & Chae, J.-C. (2019). Production of Bioethanol From Sugarcane Bagasse: Current Approaches and Perspectives. Applied Microbiology and Bioengineering, 21–42. doi:10.1016/b978-0-12-815407-6.00002-2 

11. Juwarkar, A. A., Singh, S. K., & Mudhoo, A. (2010). A comprehensive overview of elements in bioremediation. Reviews in Environmental Science and Bio/Technology, 9(3), 215–288. doi:10.1007/s11157-010-9215-6 

12. Azubuike, C. C., Chikere, C. B., & Okpokwasili, G. C. (2016). Bioremediation techniques–classification based on site of application: principles, advantages, limitations and prospects. World Journal of Microbiology and Biotechnology, 32(11). doi:10.1007/s11274-016-2137-x 

13.Mani, D., & Kumar, C. (2013). Biotechnological advances in bioremediation of heavy metals contaminated ecosystems: an overview with special reference to phytoremediation. International Journal of Environmental Science and Technology, 11(3), 843–872. doi:10.1007/s13762-013-0299-8 

14. Igiri, B. E., Okoduwa, S. I. R., Idoko, G. O., Akabuogu, E. P., Adeyi, A. O., & Ejiogu, I. K. (2018). Toxicity and Bioremediation of Heavy Metals Contaminated Ecosystem from Tannery Wastewater: A Review. Journal of Toxicology, 2018, 1–16. doi:10.1155/2018/2568038 

15. Kapahi, M., & Sachdeva, S. (2019). Bioremediation Options for Heavy Metal Pollution. Journal of Health and Pollution, 9(24), 191203. doi:10.5696/2156-9614-9.24.191203 

16. Silva, D. S.  I. G., Gomes de Almeida, F. C., Padilha da Rocha e Silva, N. M., Casazza, A. A., Converti, A., & Asfora Sarubbo, L. (2020). Soil Bioremediation: Overview of Technologies and Trends. Energies, 13(18), 4664. doi:10.3390/en13184664 

17.Chien-Sen Liao 1, Lung-Chieh Chen, Bing-Sheng Chen, Sin-Hsien Lin(2010) Bioremediation of endocrine disruptor di-n-butyl phthalate ester by Deinococcus radiodurans and Pseudomonas stutzeri.Chemosphere 2010 Jan;78(3):342-6.

18. Taqqi,M., Ali, S.,  Bhutto, L.S., Khan,S.,   Bhatti,S.,  Rauf , H., SohailM. (2019). The Role of Microorganisms in Bioremediation. International Journal of Agriculture and Biological Sciences- ISSN (2522-6584) May & June 2019 

19. Hemarajata, P., & Versalovic, J. (2012). Effects of probiotics on gut microbiota: mechanisms of intestinal immunomodulation and neuromodulation. Therapeutic Advances in Gastroenterology, 6(1), 39–51. doi:10.1177/1756283x12459294 

20.Behera, S. S., Ray, R. C., & Zdolec, N. (2018). Lactobacillus plantarum with Functional Properties: An Approach to Increase Safety and Shelf-Life of Fermented Foods. BioMed Research International, 2018, 1–18. doi:10.1155/2018/9361614 

21.Fijan, S. (2014). Microorganisms with Claimed Probiotic Properties: An Overview of Recent Literature. International Journal of Environmental Research and Public Health, 11(5), 4745–4767. doi:10.3390/ijerph110504745 

22. Liptáková, D., Matej?eková, Z., & Valík, L. (2017). Lactic Acid Bacteria and Fermentation of Cereals and Pseudocereals. Fermentation Processes. doi:10.5772/65459