Microbial processing of foods for value addition, nutritional improvement, enhancement of organoleptic characteristics, and suchlike has been a common practice for several centuries. In modern times, however, there has been an increase in demand for natural food ingredients on a global scale based on consumer perception of less toxicity and health functionality of such. Accordingly, the market for food additives obtained from microbial cultures has received expansion in several countries around the world especially due to the absence of restrictions regarding their usage in food formulations by regulatory agencies. Microbially obtained additives are appraised as natural ingredients and have been studied and found functional for quality improvement of processed foods. This chapter offers a comprehensive discourse on the fundamentals of microbial processing of foods and the technical schematics for methodologies employed for obtainment of microbially processed food additives.

Microbial electrochemical technology (MET) is a combination of microbiology and electrochemistry is primarily based on bacterial interactions with insoluble electron donors and acceptors. The metabolic activity of electroactive bacteria on different kinds of chemical compounds led to the synthesis of chemicals, bioremediation of pollutant matrices, the treatment of contaminated soils, and power generation. Predominantly, in METs, microbes are used in two areas: one area focuses on bacteria which are capable of transfer electrons to anode also called as anode respiring bacteria and the other one focuses on bacteria or archea which are capable of oxidizing a cathode also called as electrode oxidizing bacteria. Extremophiles are ubiquitous and thrive well in very harsh environments. Among them, thermophiles play a pivotal role in microbial electrochemical systems because of their unique properties such as high metabolism, physically and chemically stable enzymes and low growth. Most of the thermophilic bacterial species are anoxic or anaerobes and use oxidized compounds, for instance, SO4−, Fe (III) oxides, NO3−, and Mn (IV) as their terminal electron acceptors and physiologically capable of growing on anodes at high temperature since thermophiles are ideal candidates in microbial electrochemical system research. So far a group of microorganisms that has been examined only to a limited extent in MFCs is the “extremophiles.” Extremes in pH, salinity, and temperature when combined with materials that operate best under such conditions would potentially result in more powerful MFCs. This chapter focuses on thermophilic bacteria that function optimally under extreme conditions because they may serve as more effective catalysts with higher activity, greater stability, and longer life in microbial fuel cells.

Indiscriminate use of natural resources in all walks of life to satisfy human needs has caused us to rethink our future survival. Several times, “war for water” has been aired on Blue Planet Earth, where 71% water is found, while much less discussion has been made of the 29% land mass. Earth's land surface (29%) is divided into 70% habitable land, 10% glaciers, and 19% barren land. Agricultural activities are performed on 50% (54million km2) of total habitable land (104million km2). These data signify the importance of conserving this natural resource in a holistic way for upcoming generations. Synthesizing and using microbe-derived biopolymers is the sharp shining light in the darkness of capitalistic modernization. Agricultural activities like deep summer ploughing, tillage operations, crop rotation, land fallowing, etc. have been performed since ancient times to build up the functionally active microbiome to strengthen soil properties. Using soil microbial metabolites (also called biopolymers) for soil amelioration after implementing modern agriculture acts as a supporting tool for sustainable agriculture. Chitosan, xanthan, cellulose, dextrin, silk fibroin, and other well-documented biopolymers are obtained from soil-resident fungi, bacteria, archaea, and algae, as well as from silkworm insects. Chitosans and dextrins are used as seed coating materials to immobilize microbial metabolites and make the soil suppressive. Levans are carbon compounds secreted by both plans and fungi that regulate soil stability by binding various ions. Moreover, silk fibroins and trehalose provide the strength to the soil to bear biotic and abiotic stresses. These biopolymeric substances also confer on microorganisms the ability to overcome stressful environments such as those characterized by drought, pesticides, etc. They stabilize soil and regulate nutrients and water flow across plant roots through biofilm formation that indirectly enhances crop productivity.

Greener ways for sustenance soil fertility are to be adapted on utmost priority to prevent further degradation of sustaining properties of soil. It also helps in improving present knowledge, understanding various seasonal biochemical changes, and developing ways to sustain soil health. The soils under intensive mulberry plantation at CSR and TI, Pampore, were investigated along with fallow land in the nearby vicinity acting as a benchmark. The implications of standard chemical input applications on soil and plant health were investigated. Diverse management packages were being explored including organic matter, green manuring, biofertilizers, and reduced fertilizer applications, for sustainable crop production. Efforts are required to find out soil microbial diversity and its influence on soil health in soil ecosystem. The soil microbial load was hence determined by serial dilution method and culturing them on synthetic growth medium. The results obtained showed significant improvement in bacterial colony forming units (CFU) 1.53×106CFU/g soil sample. Similar trend was observed in case of fungal population determination where Integrated nutrient management approaches showed considerable increase AM fugal biomass with 2.43×105CFU/g soil sample, respectively, as compared to control recording a colony forming units of 1.17×105. Incorporation of green manuring has given the promising results with 25% reduction in chemical inputs and increased the OC (0.73%) content in the soil; also the beneficial endophytes associated with root and associated soils were isolated for development of biofertilizers for the sustainability of soil health. Therefore, a farmer can do additional rearing with the increased leaf yield, in turn will get additional income.

Bioactive peptides are the fragmented part of proteins which are obtained by the breakdown of proteins. Their amino acid sequence and structural characteristics are responsible for their functional characteristics. Owing to the promising effects of bioactive peptides to solve various health issues, pharma and food industries are taking interest in bioactive peptides. Fermentation of protein-rich substrates by microorganisms is a novel approach to produce peptides. This method is not only cost effective as compared to enzymatic hydrolysis but also the purification of peptides obtained through method can be done without hydrolysis. Therefore, it is quintessential to explore microbial fermentation with different protein rich substrates for the development of functional and nutraceutical foods.

Nowadays, microorganisms are capable of resolving many crises. Microbial consortia are the mixture of specific microorganisms that help us solve any particular problem. It includes bioremediation and degradation of any toxic compounds like polyethylene, hydrocarbon, chemical dyes, as well as crafting a microenvironment and boosting plant growth, secondary metabolite production, antibiotic production, etc. This chapter is a summarized form for the uses of microbial consortia. This study could help further enhance the application of microbial consortium in various fields of life sciences like agriculture, biotechnology, and microbiology.

Access to safe drinking water is one of the prime necessities of humans. Still, to date, loads of people in many parts of the world are deprived of clean drinking water. Hospitalization due to water-borne diseases amidst all technological advancement is a matter of prime concern for researchers around the globe. Analysis of supply water and water used for human consumption for pathogenic microorganisms and other harmful substances using microbes as primers is the key to determining the quality of water nowadays. Different countries are using a microbial primer as a reliable tool for examining water mostly for any microbiological contaminations. Therefore, it is important to study the potential of a diversified microbial primer system and its limitations so that the regulatory agencies can frame important directives for determining water quality. This book chapter provides a comprehensive update on the role of primer system based on microbes for managing the health risks owing to water-borne diseases and technical advances in the system for monitoring water quality.

Endophytes are the microorganisms that inhabit plants without any detriment to the latter. These microbial communities are believed to be a long associated with plants and have evolved with them. Living inside the plants, these endophytes help the plants in dealing with various kinds of environmental or biological stresses, increasing the productivity and sustainability of the plant. Endophytes achieve this by producing certain bioactive compounds (secondary metabolites or enzymes), altering the physiology of the plant, acting as biocontrol agents for both pathogenic microbes and pests, etc. This chapter reviews a variety of fungal endophytes residing in crop plants and aiding crop improvement through various mechanisms.

Microorganisms were essential components of the cycling of plant nutrients. Microorganisms play a significant role in the mobilization, uptake, growth enhancement, disease suppression, and nutrient enrichment in growing plants. Phosphate and sulfate solubilization, growth regulators promotion, siderophore production, nitrogen fixation, denitrification, immune modulation, signal transduction, and disease control are among the excellent microbial mediation processes that encourage plant production and defend it from pathogens. This chapter continues with a brief introduction of plant nutrients and their description and role of microbes in nutrient absorption. Besides, the role of various groups of microbes such as bacteria, fungi, and cyanobacteria in plant health and nutrition was being addressed in-depth in separate segments.

Energy obtained from renewable resources has become crucial to reduce the impact of Greenhouse Gases. New and renewable energy resources offer a gripping possibility as they are inexhaustible and affordable. In particular, the biogas from these sources is a useful reserve for biofuels in terms of both potentiality and heat generation. Several microorganisms such as Methanobacterium sp., Methanosarcina sp., Methanococcus sp., Methanosaeta sp., and Methanospirillum were isolated from different ecological systems and are identified for their use in the production of biogas. With rapid development in biological sciences and understanding of metagenomics, designing and construction of microbial consortia has gained notable attention and has become one of the major areas in modern renewable energy science. This chapter is focused on the use of natural and synthetic microbial consortia for digestion and degradation of waste effluents (residues from agriculture/horticulture/sericulture/forestry/fisheries, industrial, and municipal waste) to obtain biomethane and find a solution to trouble that comes up during its production in order to enhance and improve the effectiveness of the process.