eChapters

Abstract

Microorganisms execute many key functions that regulate the processes related to the fertility status, nutrient transformation, nutrient conservation, and soil health management that are crucial for agronomic sustainability. Rice soils offer peculiar conditions for microorganisms that support diametrically opposite biochemical reactions under flooded conditions. It is pertinent to note that both reduction and oxidation reactions of several essential nutrients mediated by microbes occur simultaneously in the flooded soils at various depths, profiles and stages of rice crop growth in concurrence. This is peculiar and specific to rice soils as the cultivation process demands changes in water regimes, operative and management practices.

Abiotic Stress in Plants
             
World population is growing at an alarming rate and may reach about 6 billion by the end of the year 2050. Though, the agricultural productivity is also being increased world over, yet it is not keeping pace to meet the demand of food availability. The main reasons for limiting the agricultural productivity are water shortage, depleting soil fertility and mainly various abiotic stresses and climatic change. Minimizing these loses is of primary concern for all nations to cope with the increasing food requirement. The abiotic stress is defined as the negative impact of non living factors on the living organism in a specific environment and abiotic stress is the most harm full factor concerning the growth and productivity of crops worldwide. Researches have shown that abiotic stressors are at their most harm full when they occur together in combination of abiotic stress factors (Mittler, 2006; Bianco and Defez, 2011). Numerous stresses caused by complex environmental conditions i.e. drought, too high and too low temperatures, freezing, salinity, UV light, heavy metals and recently through smog (air pollution) leading to substantial crop losses worldwide (Mahajan and Tuteja, 2005). The abiotic stresses might increase in the near future even because of global climatic change.

1.    Introduction    272
2.    Alcohols    273

    2.1.    Methanol, 274
    2.2.    Ethanol, 277
    2.3.        Butanol, 283

3.    Biodiesel    284
4.    P-series fuels

Microbial Based Formulations examines preparations produced through beneficial microorganisms, fermentation, and indigenous microbial resources. It covers Waste Decomposer, Effective Microorganisms, Fermented Plant Extract, EM-Bokashi, Indigenous Microorganisms, Fermented Plant Juice, Fermented Fruit Juice, Oriental Herbal Nutrient, and lactic acid bacteria. Water-soluble potassium, phosphoric acid, and calcium preparations, brown rice vinegar, loess powder, fermented seawater, and microorganism-enriched mixtures are also discussed. The chapter demonstrates how microbial activity and fermentation can transform locally available materials into agricultural inputs. Together, these formulations illustrate approaches for nutrient management, plant growth support, compost enrichment, and ecological farming using biologically mediated processes and farm-level resources. for preparation.

ABSTRACT

Biodiversity is often understood in terms of wide variety of plants, animals and micro-organisms existing on the earth. So far, about 1.75 million species have been identified, mostly small creatures such as insects. According to scientific estimates, there are actually about 13 million species, although range from 3 million to 100 millions. The present article deals with the importance and threats of biodiversity as well as tries to highlights the role of government and non-government sectors in conservation of biodiversity. The initial part of the article indicates the concept of evolution and biodiversity, wherein we have tried to identify the present scenario. We find that a wide range of microbial, plant and animal species are sources of various biological products for human use and welfare. These species are getting lost or extinct due to lack of conservation over a period of long time. Therefore, an effort has been made to highlight the conservation acts and important rules and regulations for protecting and conserving the bio-resources.

ABSTRACT

Soil borne fungal pathogen causing root diseases of vegetables are difficult to control by chemical methods. The existing biocontrol bacteria are not very effective in control of soil borne fungal pathogens. As such very less number of bacterial biopesticide is available commercially to control the fungal pathogens. Increasing concerns in recent years about human health and environmental problems due to chemical pesticides, couple with increasing pest resistant to chemical, have led to a reappraisal of our approach to control pest and disease in crops. The trends now are towards a management concept in which the best combination of tools is used to manage plant diseases below economic thresholds with minimal risk to human health and environment. The modern management concept includes extensive use of biocontrol agents which are harmless to non-target organisms. Development of effective technology for control of pest and disease by using microbial resources of a region to enhance the quality of ecosystem is a potential alternative approach to chemical control of plant diseases. In such strategy, search for microorganisms and biological system is an important prerequisite prior to development and practical exploitation of biocontrol. Rhizosphere microorganisms are shown to be perspective candidate for biocontrol agent as they provide the front line of defense for plant roots against the attack by various plant pathogens causing the most diseases of vegetables and crops. Chemical control of soil-borne fungal pathogen had been the subject of growing concern because of their adverse effect on the environment and emergence of chemical pesticide resistant to plant pathogen, moreover, soil borne pathogens are very difficult to control. Crop rotation, breeding for resistant plant varieties and application of pesticides are insufficient to control root diseases of important plants because they survive as sclerotia and has got wide host range.

Abstract

Microorganisms inhabiting in the rhizosphere play a vital role in ecosystem functioning. Rhizosphere is an area around the root surface where pathogenic and beneficial microorganisms repose and influence the plant growth and health. These microbial groups of bioagents found in the rhizosphere include bacteria, fungi, nematodes, protozoa, algae and micro-arthropods. Because of their rich diversity, complexity of interactions and numerous metabolic pathways, microbes are an amazing resource for biological activity. These microorganisms require organic matter for their growth and activity in soil and provide valuable nutrients to the plants and hence maintaining the plant health. The most promising fields for the use of bioinoculants are agriculture, horticulture and forestry. There are many reports on the inoculation of bioagents in agriculture and horticulture crops but only a few reports are available in forestry. This article is an overview on various bioinoculants which are used during inoculation and a compilation of scattered reports of bioinoculants in forestry only.

Soil microbial biomass is an important parameter linking the plants to soil. It comprises about 2-3% of the total organic carbon in the soil and recognized as an important source of nutrients to plants. It is also a dynamic component of the soil associated with several functional properties of the terrestrial ecosystem. It represents the fraction of the soil responsible for the energy and nutrient cycling and the regulation of organic matter transformation.

Microbial biomass is a small but labile and living component of soil organic matter that is involved in most bio-geo-chemical processes in the terrestrial ecosystem. It interacts with crop productivity by regulating nutrient availability as a source; determining soil carbon storage- sink; and contributing to the atmospheric CO₂ from respiration. Thus it is the main agent that controls the flow of carbon and cycling of nutrient elements.

There is a close relationship between soil microbial biomass, decomposition rate, and nitrogen mineralization. It is also positively correlated with grain yield in organic farming and also contributes to soil structure and stabilization. Thus, there is the immense importance of microbial biomass in soil fertility as well as in agriculture.

Abstract
Microbial bioprocesses are essential for maintaining the vitality and functionality of aquatic ecosystems, playing a key role in important biogeochemical cycles including those of carbon, nitrogen, and sulfur.
Bioprocesses such as bioremediation, biofertilization, biofilms, biofloc technology, probiotics, bio-bleaching, bio-corrosion, and bio-fouling. these processes are applied in different domains including wastewater treatment, aquaculture, and environmental clean-up. In wastewater treatment, techniques like activated sludge and biofilms are utilized for the removal of nutrients and the breakdown of pollutants. In aquaculture, microbial management and probiotics help in sustaining water quality and improving the health of aquatic species. In bioremediation, microbes areemployed to tackle contaminants like heavy metals, oil spills, and pesticides, with advancements in microbial consortia enhancing the effectiveness of pollutant-specific degradation. the role of microorganisms as bioindicators and biosensors. Recent developments in microbial biotechnology feature progress in genetically engineered microbes, the use of synthetic biology, and the implementation of microbial fuel cells (MFCs) for generating bioenergy. Challenges and limitations, including environmental constraints, the potential risks of genetically modified organisms, and the feasibility of large-scale applications.
Keywords: Bioremediation, Biofertilization, Biofilms, Biofloc, Probiotics, Bio-Bleaching, Bio-Corrosion, Bio-Fouling

1. Introduction
Pharmaceutical pollution has emerged as a significant global concern, raising alarms about its potential impacts on ecosystems and human health. The journey of pharmaceutical compounds from their point of use to contamination of water bodies reveals a complex and interconnected web of anthropogenic activities. From manufacturing plants to individual households, these pollutants persistently infiltrate aquatic systems, creating a growing

13.1 Introduction

Many changes have occurred in egg production and processing, as well as in the egg itself, over the last 40 years. All of these changes have contributed to the microbial challenges of the egg that we face today. In the past, production traits including egg size, feed conversion and egg output have received the majority of attention in genetic selection of laying hens. Microbial integrity hasn’t been given much attention. Until the 1990s, food safety concerns associated with shell eggs were not considered. Eggs were thought to be pathogen free until they were cracked.

Fungi include a large group of organisms and there are about 72,000 described species and the total number of species in the world may be as high as 1.5 million (Hawksworth et al., 1995). The infections that these fungi cause on a group of organisms viz. plants, animals, insects etc. may or may not be beneficial depending upon the type of host infected. With reference to insects, fungal infections in pest insects are beneficial which can be used effectively in biocontrol programmes. On the other hand, fungal infections in beneficial insects are harmful.

The entomopathogenic or entomogenous fungi mainly include those genera of fungi that associate with insects and some arthropods in a variety of ways. The association with the insects may be saprophytic, commensalistic, parasitic or pathogenic with the insect host. Some entomopathogenic fungi like Coelomomyces are obligate pathogens which can’t be cultured outside a living host, but most of them are however, facultative pathogens capable of growing without host insect. More than 750 spp of fungi, mostly deuteromyctes and entomophthorales from about 100 genera are pathogenic on insects and many of them offer great potential for pest management. The entomopathogenic fungi which have been most intensively investigated include Beauveria, Metarrhizum, Paecilomyces, Entomophthora, Verticillium, Hirsutella, Eryina, Mefarrhizium etc. Out of them Beauveria and Mefarrhizium have been extensively used in large scale for the control of several crop pests.

Abstract

Now a days, the public has become more sensitive towards the protection of the environment and general awareness has increased about the adverse effects of industrial effluents contaminate with various pollutants, including dyes on the environment. Dyes are an important class of synthetic organic compounds used in many industries, especially textiles. Consequently, they have become common industrial environmental pollutants during their synthesis and later during fiber dyeing. Textile industries are facing a challenge in the field of quality and productivity due to the globalization of the world market. The dyes, which are widely used in textile industries when left in water bodies without any treatment cause environmental pollution and in turn are toxic, carcinogenic and mutagenic. The efficient treatment of the sludge from the industries is not economical and a challenging task. Currently, a number of different technologies and methods such as biological, physical and chemical are widely used for the removal of dyes. The treatment technologies for the removal of textile dyes from the textile wastewater found that over the past two decades interestingly focused on biodegradation methods such as microbial decolourization, enzymatic decolourization, adsorption by microbial biomass (living or dead) and bioremediation systems as a better alternative as the available physico-chemical methods.

Biodiversity is the variety of life in different microbes, animals, plants and their genes present in the ecosystem. Soil provides a vital habitat and environment primarily for microflora such as bactria, actinomycetes, fungi as well as microfauna viz. protozoa and nematodes, mesofauna such as microarthopods, enchytraeids, macrofauna such as earthworms, beetles, termites and millipedes (Gaur 2006a).

Biodiversity and soil are interlinked which interact closely with wider biosphere. Conversely, biological activity is ofprime importance in influencing the physical and chemical conditions of soil (Bardgett 2005). The level of soil biological activity is, therefore, affected by soil type and also depends on the use of management practices which contribute to crop productivity.

Soil biodiversity and soil processes

A majority of soil organisms participate in various processes which are essential for the biosphere. The main ecological function is to decompose organic matter largely derived from the plant and animals residues Which consist of celluloses, hemicelluloses and lignin, and to supply plant nutrients to support growth. These organisms participate in various nutrient cycles and processes such as nitrogen mineralization, nitrification, nitrogen fixation, transformations ofphosphorus, potassium, sulphur, calcium, magnesium, iron and micronutrients (Pankhurst et al 1997). They participate in bioremediation of harmful compounds such as heavy metals and pesticide residues (Gaur 2006 b). They not only maintain physical and chemical conditions of soil, but also regulate emissions / assimilations of green house gases and suppress soil borne diseases and pests

Introduction

In poultry, the intestine is home to trillions of microorganisms, with bacterial concentrations reaching up to 10¹² bacteria per gram of digesta. In a healthy digestive system, this microbial community is highly diverse and metabolically active, supporting crucial functions in digestion, immune defense, and overall health. The gastrointestinal tract (GIT) of a newly hatched chick begins as a sterile environment but quickly develops a complex microbiota as the bird matures. The composition of gut microbiota is highly variable, shaped by environmental factors, diet, the genetic makeup of the host, and other influences. This dynamic microbiome plays a pivotal role in nutrient absorption, disease resistance, and growth efficiency, making it a central focus in poultry health management and productivity enhancement.The health and productivity of poultry are fundamentally influenced by the gut microbiome, which shapes digestion, immunity, and growth potential. Microbial diversity variesacross several poultry species, including broilers raised intensively, native chickens in free-range conditions, and unique species such as Guinea fowl, Kadaknath, and red jungle fowl. Using advanced metagenomicsanalysis of microbial diversity, structure, and function, highlighting the implications of microbiota composition on poultry health and productivity possible. The gut microbiota is increasingly recognized as a major determinant of health and productivity in poultry. It not only influences nutrient absorption and metabolism but also plays a critical role in immune response and pathogen resistance. Intensive farming practices have altered gut microbial ecosystems in commercial broilers, often reducing diversity compared to native breeds and heritage species raised in field conditions.

The traditional fermentation process is an uncontrolled system and is usually carried out in a quite unhygienic environment. As the process of fermentation is brought about by the microbial activity so in the traditional system of fermentation there is every possibility of inclusion of microorganisms which is not desired in or that can cause spoilage to the finished product. Although no incidents of food poisoning has been reported due to consumption of fermented fish there are also no reports of any clinical investigations in this regard. A study on the microflora of such a fermented fish product is useful to understand -how safe is the product for consumption. The diverse groups of microorganisms that are present in the fermented fish products will provide information about their characteristic nature -beneficial or pathogenic, their contribution towards production of flavour and aroma, etc. The environment, however, is the key factor for the so called ‘microbial diversity’ among different fermented fish products round the globe. Moreover, the aquatic habitat, processing technique and of course, the handling during processing are the other factors that equally make a way for the introduction of a variety of microorganisms in the finished product. A study on different curing stages i.e. fresh, semi-cured and fermented, is therefore necessary to understand the pattern of microbes and become evident the role played by the microbes during fermentation.

1.    Introduction    129
2.    Soil Microbiology    129

    2.1.    Bacteria, 130
    2.2.    Fungi, 132
    2.3.    Algae and Cyanobacteria, 132
    2.4.    Protozoa, 132
    2.5.    Viruses, 135

3.    Water Microbiology    133
4.    Microbial Associations    133

    4.1.    Neutral interactions, 133
    4.2.    Positive interactions, 133
    4.3.    Negative interactions, 133

Several attempts have been made to detect the biopotentials of microorganisms with reference to their ability to produce various enzymes with a view to use them in industrial processes and bioremediation applications. Enzymes are increasingly used as a new route to synthesize food ingredients such as flavours, emulsifiers, sweeteners, food additives, nutrients. With the advent of genetic engineering, a wide range of enzymes has become available on a large scale and this has increased the scope of enzyme technology.

MICROBIAL ENZYMES: Enzymes are proteinaceous complex organic catalysts of biological origin and vital constituents of cells. Microbes produce a variety of enzymes, intracellular and extracellular enzymes. Most of the microbial enzymes produced for commercial usage are extra cellular enzymes. Extracellular enzymes are secreted outside the cell and hydrolyze polymeric substances. Amylases and proteases are enzymes of economic importance. At present over 60 enzymes are in commercial use, of which three-quarters are hydrolytic enzymes. Commercial production of microbial enzymes utilizes a variety of fungi, yeasts and bacteria. The composition of the medium, genetic stability of the microbial strain and physical and chemical factors of fermentation influence the production of a particular enzyme.

Enzymes catalyze a variety of reactions during processing and preservation of food products and form a large group of processing aids. Food industry utilizes enzymes in the production of bakery items, dairy products, fruits and vegetables juices and products, tenderization of meat, modification of oils and fats, flavour production and preservation of food products. Enzymes have also found use in the manufacture of ingredients like glucose, high fructose syrup, citric acid, colour and flavour constituents.

The study of soil microorganisms involves various complicacies when compared with those of plants or animals aboveground. The complicated heterogeneous environment existing in soil and the varied growth behaviour of microbial populations in soil have necessitated the development of special techniques to study the microbes and their metabolic diversity, individually and holistically without disturbing their natural habitat. With the gradual improvement in microscopy since its discovery in 1667 and also with the greater understanding of the nature of soil microbes and their properties in relation to total ecosystem function, the concept of studying microbes in isolation has enormously changed. Microscopes have helped in magnifying these, otherwise invisible, minute creatures within the limits of naked eyes.

SINGLE CELL PROTEIN (SCP) AND PROTEIN DEFICIENCY

Protein is an essential component of diet. The greatest single problem in the world today is global food protein shortage. Having adequate quantity of food is only one side of the picture, but the most important aspect is the supply of balanced and nutritious food. All efforts are being made to increase the food production through modern methods of farming. But very little attention is being paid towards protein requirements and production. Approximately half of world population suffers from the protein deficiency disease called ‘Kwashiorkor’ and children with poor protein are victims of this disease.

Usually, cereals have low protein values while protein rich pulses are not available in desired quantities due to poor yields and high costs. The good quality protein available in fish, meat, poultry, and eggs is not available due to poor economic condition as well as varied dietary habits. With the current system of production, agriculture cannot be relied upon to feed an ever increasing world population. Hence there is an urgent need to find other protein sources. The best potential is seen in microbial protein or single cell protein (SCP), a new source of protein independent of agriculture.

DEFINITION: The dried cells of microorganisms such as bacteria, fungi, yeasts, algae that are grown in large scale culture systems as proteins for human or animal consumption are collectively known as "single cell proteins".

2.1 Introduction 
The world is encountering a severe power and environmental crisis. Adopting sustainable progress is the best means to protect our environment and maximise the use of available resources. The urgent issues, encompassing diverse types of pollution and carbon emissions, highlight the necessity to shift towards renewable energy sources. This shift is essential for diminishing our dependence on fossil fuels, addressing the on-going challenges regarding climate change, and confronting the exhaustion of current energy reserves. Furthermore, mitigating water pollution is an essential component of ensuring ecological sustainability [1,2]. Water supplies are rapidly being contaminated due to diverse contaminants including heavy metals, and harmful chemicals. While industrialization is critical for societal growth, it is critical to recognise the negative environmental consequences caused by numerous processes that emit hazardous substances. Improper disposal of untreated wastewater can negatively impact ecology and biodiversity [3]. As a result, it is critical to use environmentally friendly and sustainable treatment methods that adhere to green development principles. This will bolster industrialization efforts while upholding water pollution safeguards for recovery and reuse. Given the prevailing energy crisis, traditional wastewater treatment facilities have become financially unsustainable due to their high energy consumption. Traditional wastewater treatment is both costly and demands substantial energy resources. Furthermore, these approaches fall short of efficiently eradicating recalcitrant organic waste, heavy metals, and other persistent contaminants. Moreover, many of these treatment processes require regeneration. Microbial fuel cell (MFC) technology has emerged as an ecofriendly treatment option capable of effectively eliminating stubborn organic pollutants and heavy metals over the long term. Microbial fuel cells are chosen over other current treatment methods because to their reduced energy needs and lower chemical usage [4,5]. In addition to lowering energy usage, MFCs possess the ability to produce ample bioenergy, which can help alleviate the energy shortage. This provides a cleaner alternative for generating renewable energy in favour of sustainable development and environmental protection as depicted in Figure 2.1.

Introduction

Hippocrate, an ancient physician, a great thinker and also often referred as father of medicine, for the first time conceive the idea nearly 2,500 years ago that a disease is caused due to natural factors such as environmental factors, diet, and living habits. He advocated the secret of healthy living in healthy food in his famous quote “Let food be thy medicine and medicine be thy food”. But unfortunately, this wisdom about food has faded with the time and we became dependent on synthetic medicines and drugs for even life style disorders. In the last century, research advancement in the field of food science and nutrition established food not only as a source of nutrition but also a source of active food components that aid specific functions and rejuvenated the Hippocrates concept. According to the Department of Health and Human Services, USA, daily diet of a person, plays a crucial role in 5 of 10 diseases which are the leading causes of death, such as diabetes (noninsulin dependent or type 2), stroke, coronary heart disease (CHD), specific type of cancer, and atherosclerosis. In the mid-1980s, term “functional food” was introduce in Japan and defined as food that contain active components either from plant or animal origin and provide physiological benefits in addition to the basic nutritional needs.

Genetics is the study of what genes are, how they carry information, how their information is expressed, and how they are replicated and passed to subsequent generations or other organisms.

DNA in cells exists as a double-stranded helix; the two strands are held together by hydrogen bonds between specific nitrogenous base pairs: A-T and C-G.

A gene is a segment of DNA, a sequence of nucleotides, that code for a functional product, usually a protein.

When a gene is expressed, DNA is transcribed to produce RNA; mRNA is then translated into proteins. This is also referred as Central Dogma of Life. The DNA in a cell is replicated before the cell divides, so each daughter cell receives the same genetic information.

The term growth for bacteria and other microorganism usually refers to changes in the total population rather than an increase in size or mass of an individual organism. As the mechanism of conservation and dissipation of heat generated during metabolism lacks in bacteria, the enzyme system in bacteria gets directly influenced by temperature. The purpose of studying the bacterial growth curve is a) to become familiar with the population growth dynamics of bacterial culture and b) to plot a growth curve and determine the generation time of bacterial culture.

A number of methods are now available for measuring bacterial growth. Some important ones are

1)By colony counting or cell counting

2)By weighing the cells

3)By cell activity (turbidity method)

Abstract

Discovery of the agricultural utility of microbes during the later part of the eighteenth century, led to the formulation and utilization of superior microbial strains as biofertilizers, for a wide variety of crops and growing conditions across the world. Though microbial inoculants have been in usage for almost two centuries, they are yet to capture the collective imagination of farmers across the globe, which is essential to meet the larger objective of reducing chemical input usage in cropping systems. One probable reason for this is the existence of large growing tracts that are subject to various abiotic stresses of atmospheric and edaphic origin, which limit the proliferation and efficiency of the microbial strains that are commonly used in inoculant production.  This is obvious, since unlike chemical fertilizers, microbial cells being living systems need to grow and thrive in the introduced eco-systems in order to achieve the desired effects of inoculation. But unfortunately microbial inoculant technology has largely adopted the one size-fit all mindset, which had led to failures of microbial inoculants especially in abiotically stressed growing environments. In such a scenario it would be wise to adopt a location or region specific approach for the selection of superior and locally adapted microbial strains for inoculant production.

Introduction

The increasing concern about the long-term productivity of agro ecosystems has emphasized the need to develop a management strategy that maintains and protects the soil resources. This is directly related to the maintenance of the level of soil organic matter and nitrogen status, which are the critical components of soil productivity. These parameters can change over time due to crop management practices such as cultivation, crop rotation, residue management or fertilization which, in turn, can influence the long-term sustainability of ecosystem. Application of chemical fertilizer is one of the most expensive inputs in agriculture. About 65% of the applied nitrogenous fertilizer is lost from the plant–soil system through gaseous emissions, runoff, erosion and leaching which causes greenhouse effects and nitrate pollution of surface and ground water (Rejesus and Hornbaker 1999). Similarly, P applied in soil is rapidly fixed and results in low P availability for plant production. In this context, the deployment of microbial biofertilizers promise increasing soil nutrient availability in integrated nutrient management system.

The increase in population and global industrialization has led to environmental pollution, which is a significant threat to the health of the ecological system. Different measures are recommended to remediate polluted areas effectively. The applications of nanotechnology in medicine, cosmetics, sports, textiles, and pharmaceuticals have increased over the years. Another approach to remediate the adverse effects of pollutants on the environment is by utilizing nanotechnology for contaminant remediation. Biogenic nanoparticles are tiny particles produced by biological entities such as fungi, bacteria, yeast, and algae. These biogenic nanoparticles are efficient in removing pollutants like heavy metals, pharmaceutical waste, dyes, and hydrocarbon waste. 

1.    Introduction    174
2.    The Thermodynamic and Mechanistic basis of Cellular Metabolism    174

    2.1.      Adenosine triphosphate, 175
    2.2.    Coenzyme A, 176
    2.3.    Modes of ATP synthesis, 177

3.      Components of Electron Transport Chain    181

    3.1.    Electron carriers in ETC, 182
    3.2.    Complex I - NADH dehydrogenase (NADH coenzyme Q reductase), 185
    3.3.    Complex II - Succinate - coenzyme Q reductase, 187
    3.4.    Complex III - Coenzyme Q - cytochrome c reductase, 187
    3.5.    Complex IV - Cytochrome c oxidase, 188
    3.6.    ATP synthese, 188

The essential nutrients and their function in microbial cells

1. INTRODUCTION

Flavour is a distinctive property of a substance affecting the gustatory sense. It may be defined as “The sum of those characteristics of any material taken in the mouth, perceived principally by the senses of taste and smell, and interpreted by the brain.” Flavour perception is a complex process which requires the particles to be mixed with saliva and salivary enzymes to promote the release of flavour. Flavour molecules are very diverse in nature. More than 5000 compounds in food have been identified as flavour components which can be detected at very low concentration and are thus, used in products at very low levels. Hexenols and hexenals, characteristic of green taste of fresh fruits and vegetables, can be perceived at a concentration of about 1 part per million (ppm). Naturally occuring flavour compounds are present at a very low concentration ranging from parts per trillions (ppt) to parts per millions (ppm) level. Majority of these compounds are volatile, with boiling points in the range of 20-300 °C. Most of these compounds are lipophilic and possess a great diversity of chemical group and structure with molecular weight ranging between 50-250 g/mol.

Flavour and fragrance compounds are a part of expanding industry with an estimated cost of nearly $27 billion. These comprise of diverse molecules with unique structures and functional groups that contribute to varied aroma and flavour, ranging from floral to fruity notes. The processing operations modify the equilibrium between the different components in raw food that might weaken the original flavour, which require subsequent supplementation. These flavour supplements can be natural or chemically synthesized. Of all the available flavour compounds, around 80% are produced by chemical synthesis whose use is limited due to formation of racemic mixtures and lack of substrate specificity. The growing awareness of consumers towards chemicals supplemented to food has led to the development of the flavouring compounds of biological origin referred to as natural flavours or bioflavours. The first major source of flavour compounds was primarily from plants. Identification of microbes producing vital food flavourants paved the way for alternative low cost, efficient and flexible method for the commercial production of flavour compounds.

Abstract
 
Opencast mining destroys the original land ecosystem and microbial community due to mining and stockpiling of mine rejects on adjoining land, which is a matter of great environmental concern. Mining creates formation of wastelands, formation of gullies, ravines, overburdens, reduced water infiltration and increased runoff. Reclamation of mined out areas is often difficult due to its chemical, physical and biological traits. Absence of topsoil is the most common feature of the mine spoils dumps. Arbuscular mycorrhizal fungi (AMF), the synonym of VAM fungi, are important microbes of soil that form symbiotic association with most of the terrestrial plants on the earth. Observations led to use of legume microsymbionts as biological substitutes for fertilizers. AMF diversity increases with species diversity of plants as the potential number of association increases. Dominant arbuscular mycorrhizal fungi can prevent the invasion of non-mycorrhizal plants on land where they have established symbiosis and promote their mycorrhizal host.

Introduction

Bacteria are very minute and colourless in their natural environment and are difficult to be seen under compound microscope. To view their exact morphology, various kinds of stains are used. Stains are of three main types.

Acidic stains: These are those stains in which charge on dye ion is negative. e.g. India Ink, Eosin etc.

Basic stains: These are those stains in which charge on dye ion is positive. e.g. Methylene blue, Crystal violet etc,

Neutral stains: These are the salts of dye acid in dye base. e.g. Eosinate of Methylene blue.

Abstract

Anaerobic sulfur compound reduction processes make use of sulfur, thiosulfate, trithionate, tetrathionate, and sulfite during the reduction process. Complete reduction of these sulfur compounds leads to production of H₂S. Isolation of sulfur compound reducers requires a suitable electron donor and one of the sulfur compound as a sole electron acceptor during the reduction process carried out in anaerobic conditions. Anaerobic sulfur, thiosulfate and tetrathionate reductases identified to date are molybdopterin binding oxidoreductases that extract out electron during the reduction process. The electron transport chain during the reduction process involves cytochromes and menaquinones. Dissimilatory sulfite reductases include conventional siroheme dissimilatory sulfite reductase and the nonconventional sulfite reductases including ASR sulfite reductase, F₄₂₀ dependent sulfite reductase and the MccA sulfite reductase. Anaerobic sulfur compound reduction process are almost ubiquitous in nature and are important part of the biogeochemical cycle. They occurs in aquatic systems, are found in extreme environments such as hydrothermal vents, acid mine drainage sites and are also found in important human and animal pathogens.

Abstract

Microbiological synthesis of nanoparticles has emerged as rapidly developing research area in nanotechnology across the globe with various biological entities being employed in production of nanoparticles constantly forming an impute alternative for conventional methods. Simple prokaryotes to complex eukaryotic organisms including higher plants are used for the fabrication of nanoparticles. In the present article, the synthesis of important plant nutrients like Mg, Zn, Ag, Au, Ti, P and Fe nanoparticles from different fungal species, their characterization and application potential of nanonutrients in agriculture is elaborately discussed.

Introduction

A toxin (Greek: ôïîéêüí, toxikon, lit. (poison) for use on arrows) is a poisonous substance produced by living cells or organisms that is active at very low concentrations. Toxins can be small molecules, peptides, or proteins and are capable of causing disease on contact or absorption with body tissues by interacting with biological macromolecules such as enzymes or cellular receptors. Toxins vary greatly in their severity, ranging from usually minor and acute (as in a bee sting) to almost immediately deadly (as in botulinum toxin)

Soil microorganisms immobilize and mineralize various elements to satisfy their growth requirements. The subsequent turnover of microbial biomass also releases several mineral elements. The elements may be released as a result of organic matter decomposition (e.g. during the process of mineralization, ammonification, etc.) or through biological weathering. Other transformations may involve oxidation and reduction of various inorganic ions and compounds which are mostly catalyzed by chemoautotrophic bacteria during oxidation of ammonium, nitrite, sulphur, iron, etc. Such oxidations may also release energy for microbial growth.

Introduction

Phosphorus is only second to nitrogen as a mineral nutrient required for plants, animals and microorganisms. It is a major constituent of nucleic acids in all living systems essential in the accumulation and release of energy during cellular metabolism. Phosphorus is found in soil, plants and microorganisms in number of organic and inorganic compounds. It is the second major inorganic nutrient after nitrogen in term of quantitative requirement for both crop plants and microorganisms. This element may be added to soil in the form of chemical fertilizers, or it may be incorporated as leaf litter, plant residues or animal remains. In cultivated soils it is present in abundance (i.e. 1100 kg/ha), but most of which is not available to plants, only 15% of total soil phosphorus is in available form. Thus, phosphorus occupies a critical position both in plant growth and in the biology of soil.

Introduction

In soil, microorganisms influence not only the availability of carbon and nitrogen, which are important constituents of plants, but also of sulfur (S), phosphorus and many other trace elements for plant absorption. Sulphur is found widely distributed and considered as tenth most abundant element in the nature. Sulfur is considered as an essential element for survival of plant and animals and found as gypsum (CaSO₄.2H₂O), pyrite (FeS₂) and other combined form and also in elemental form (S⁰) in the nature. The requirement of sulphur by plant is comparatively less than the primary nutrients, hence sulfur is recognised as ‘secondary’ nutrient. 

The planet earth harbors a total population of 7,530,687,482 (as on 7^th September 2017 at 1345hrs) in which Asia and Africa share 4,486,207,286 and 1,252,251,830, respectively. In majority of the countries in Asia and Africa surveillance programs for detection and source tracking of human health hazard bacteria in foods is scant and in some cases do not exist. Hence, the task is much more complicated especially catering to needs of food, nutritional security and microbial safety of foods of more than 5,738,459,116 or 76.2 % of the total population of the world. The continued occurrence of foodborne illness is not evidence of the failure of our food safety system. In fact, many of our prevention and control efforts have been and continue to be highly effective. In advanced countries like US where food supply is one of the safest in the world, however, significant food borne illness continues do occur. Despite great strides in the area of microbiological food safety, much remains to be done.

Food-borne disease outbreaks are defined as the occurrence of 2 or more cases of a similar illness resulting from ingestion of a common food or observed number of cases of a particular disease exceeds the expected number. These can be confirmed (when at least one causal agent is identified) or suspected (based on clinical and epidemiological information). Although most cases are sporadic, these diseases draw attention to themselves due to outbreaks, thorough investigation of which can help in identifying control measures.Annual burden of foodborne diseases in the WHO South- East Asia Region includes more than: 150 million illness, 175 000 deaths, 12 million DALYs (Source: FERG Report 2010).

4.1 Introduction
At the moment of secretion in the udder, milk is sterile; however, it is contaminated by bacteria before it is extracted from the udder. With the exception of mastitis, the bacteria are generally innocuous and restricted at this juncture. Microorganisms may contaminate the milk further during milking, handling, storage, and other pre-processing activities. The bacteria have the potential to either enhance the quality of milk or cause it to deteriorate. Some of the beneficial bacteria, particularly the lactic acid bacteria, are referred to as probiotics. These probiotics are gaining a more prominent position in nutraceutical dairy and other food products, which provide consumers with health benefits such as the control of diarrhoea, antihypertensive, hypocholesterolemia, immunostimulatory, and anticarcinogenic properties.

4.2 Lactic acid bacteria
This particular group of bacteria is capable of homofermentation, which is the process of fermenting lactose to lactic acid, and heterofermentation, which is the process of generating a high number of end products. They are commonly present in milk and are also used as starter cultures in the production of cultured dairy products, such as yoghurt.

Introduction

Numerous characteristics of food determine its acceptability to consumers and to regulatory officials. Before accepting a food for consumption, it must be attractively presented, must have desirable odour and flavour characteristics and other qualities and must be free from potential pathogens or their toxic products. The ultimate nutritive qualities, flavour and appearance have been preserved and no harmful organisms or substances are present to affect the consumer adversely. If the quality of the product is good, its keeping quality is also likely to be substantial. Conversely, there are more chances of spoilage of an inferior quality food product during storage.

1. Introduction

Fruits and vegetables have been an integral part of man’s diet from immemorial times. Fruits are the portions of plants that bear seeds, while vegetables are the edible components of a plant, including the leaves, stalks, roots, tubers, bulbs, flowers and seeds. These can be eaten raw or cooked. Fruits and vegetables can be preserved for short-term intervals under refrigeration, with or without receiving a minimal treatment like slicing, chopping, shredding or peeling. Fresh produce may also be irradiated or packaged in controlled or modified atmosphere in films for short-term storage. Long-term preservation includes canning, juicing, drying and addition of preservatives. Food contamination with hazardous biological agents remains a worldwide challenge in food safety and nutrition (Kenny 2002; Schlundt 2002; Tauxe et al 1997). Microorganisms form part of the epiphytic flora of fruits and vegetables and many will be present at the time of consumption. Production practices, growth conditions and the location of the edible part during growth (soil, soil surface, aerial part) will in combination with intrinsic, extrinsic, harvesting and processing factors affect their microbial status at the time of consumption. Man-made sources may be directly from farm laborers and from the equipment used for harvesting or storage. The types of microorganisms on fruits and vegetables would also vary with the orchards, vineyards or growing fields. The resident microflora normally subsists on the slight traces of carbohydrates, proteins and inorganic salts that dissolve in the water exuding from or condensing on the epidermis of the host. The numbers of bacteria present will vary depending on seasonal and climatic variation and may range from 104 to 108 per gram. The inner tissues of fruits and vegetables are usually regarded as sterile (Lund 1992). However bacteria can be present in low numbers in the insides of the fruits and vegetables as a result of the uptake of water through certain irrigation or washing procedures.

In the last decade or so, the problem of determining the microbial content and their activities in dairy products has been under close scrutiny. The dairy industries still adopt the dye reduction test because it is cheap, simple and satisfactory. However, other new techniques have been introduced along with some modifications in traditional tests. The microbiological quality must be maintained. To assess the bacterial content and their activities in dairy products, various methods are available for the microbiological testing of milk. The specific tests should be chosen as per the application and other factors like cost etc. On the basis of public health and economic consideration it is necessary to test microbiological quality of milk at a number of points along the chain from producer to consumer which includes - raw milk supply, bulk milk arriving at processors premises, monitoring bulk milk during storage prior to processing and monitoring the procession & the quality control of finished products. The techniques for estimating bacterial numbers in raw material are divided into two categories.

Introduction

In this microbiology report, we delve into the intricate realm of bacterial isolation and identification, exploring the fundamental processes that unlock the mysteries of microbial worlds. From the methods employed for isolating bacterial strains to the intricate techniques of identification, this report aims to provide a comprehensive understanding of the crucial role microbiology plays in unraveling the secrets of these microscopic organisms. Join us on a journey through the principles and applications that form the backbone of bacterial isolation and identification in the fascinating field of microbiology.

This chapter introduces the microbiological characteristics of eggs and egg products, beginning with the egg's natural physical and chemical defenses against microorganisms. It examines routes of contamination, spoilage microorganisms and spoilage patterns, with particular emphasis on Salmonella Enteritidis and its public-health significance. Other pathogens of concern and the distinctive microbiology of processed egg products are also considered. The chapter discusses microbiological testing, indicator organisms, contamination control and predictive microbiology, providing a foundation for designing effective safety systems throughout the egg value chain.