eChapters

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.

1. Bacteria intoxication - already formed bacteria not live bacteria

2. Bacterial infection consumption of live bacteria

3. Neuro toxin produced by C. botulinum

4. Listeria identified by the serotyping

5. Fishery product have type E, C. botulinum

6. S. aureus produced entiro toxin

7. S. aureus is heat resistant but not active in pasteurization

8. E. coli-0157:H7

9. Salmonella should be below 105/g

10. Septicemia can occur due to the salmonella

11. L. monocytogens should be 10/ g

Microorganism is a collective term for all living organisms, which are not visible to the eye, and occupy an intermediate position between the vegetable and animal kingdoms. They are found every where in the atmosphere, in water and in the soil and, as they break down organic materials, they play a very important role in the cycle of the nature.

There are thousands of species which are important to the life and economic structure of the human race. For example, certain species form simple chemical elements during the break down of dead organic material which plants can use again. They increase soil fertility and crop production which results in more food.

Other species are present, and essential, in animal intestines, helping in the digestion of food.

Some microorganisms are used in many food processes, e.g. dahi, yoghurt, cheese, pickles, beer and wine as well as in the acid production to preserve foods. There are microorganisms that produce toxic substances which kill other organisms, e.g. the mould penicillium which produces the substance penicillin.

Many microorganisms cause diseases in animals and plants with a subsequent reduction in the nation’s food supply, whereas others cause food deterioration such as mouldy foods, tainted foods, etc.

A. Enumeration of Different Microflora of Soil
Introduction
Agriculturally, soil is the region which supports the plant life by providing mechanical support and nutrients required for growth. From the microbiologist view point, soil is one of the most dynamic sites of biological interactions in the nature. Soil is an admixture of five major components viz. organic matter, mineral matter, soil-air, soil water and soil microorganisms/living organisms. The amount/ proposition of these components varies with locality and climate.

The soil organisms are broadly classified in two group’s viz. soil flora and soil fauna, the detailed classification of which is as follows.
1) Soil flora
a) Microflora Bacteria, Fungi, Molds, Yeast, Mushroom, Actinomycetes, Streptomyces, Algae e.g. BGA, Yellow Green algae, Golden brown algae.
b) Macroflora

The basic methods for wastewater sewerage (collection, treatment, and disposal) are as follows:

• Off-site sewerage
• Separate sewerage system
• Combined sewerage system
• On-site sewerage

Many nations have implemented separate sewage systems that transmit sewage and storm water through separate pipelines in order to separate the two. Storm water often does not contribute to a wastewater treatment facility (WWTP). Domestic sewage contains 99.9% or more water. The remaining portion is made up of bacteria

Life on Earth is dependent on microorganisms for many essential services. Microbes are intimate partners in global agriculture by way of mobilization of nutrients, antagonism against pathogens and exploitation of plant- microbe interactions and optimization of plant microbiome allows farmers to apply less chemical fertilizers and pesticides, and improving plant growth and yield for sustainable development.

India has 2.4% of land area of world and 8.1% global species diversity. India has 7500 km long coast line in nine states and three union territories. About 14% of Indian population (17 crores) lives in coastal area. In 10.78 million ha of coastal ecosystem, rice is the major coastal crop. Coastal rice accounts for 15% of total area and production of India. Coconut, cashew, areca nut, spices, plantation and fruit crops are the other important coastal crops. The east coast in four states (Tamil nadu, Andhra Pradesh, Orissa, West Bengal) and one union territory (Pondicherry) has sandy coast and plains with medium to high rainfall (100-250 cm), and hot humid climate. It has marshy lands and mangroves. The west coast in five states (Kerala, Karnataka, Goa, Maharashtra, Gujarat) and two union territories (Diu and Daman, Dadar and Nagarhaeli) has fertile sandy plains with high rainfall (250-300 cm) and hot humid climate suitable for horticulture and plantation crops. Western Ghats near west coast is a hot spot with high biodiversity. ICAR established the Central Coastal Agriculture Research Institute (CCARI) at Goa in 2015 to carry out research on coastal agricultural crops.

Soil salinity in coastal regions is not only a soil type character, but also due to low quality irrigation water. The plant associated microorganisms “Plant microbiome” play a significant role in conferring resistance to soil salinity. The endophytic bacteria- rhizobium, rhizobacteria- azospirillum, azotobacter, phosphobacteria, PGPR bacteria, cyanobacteria, symbiotic fungi- ecto and endo mycorrhiza, alleviate the impact of soil salinity. Minimal microbiome for plants is the key determinant of plant health and productivity. The plant- microbe interactions are of three types: (i) Positive: Beneficial organisms- nitrogen fixers, phosphobacteria, mycorrhiza; (ii) Negative: Harmful organisms - plant pathogens; (iii) Neutral: Transient organisms. Millions of microbes inhabit plants, form complex ecological communities to improve plant growth, crop quality and productivity.

Abstract

Cow and buffalo milk is the major source milk worldwide contributing 81 and 15% of total milk production respectively. However, milk from animals like goat, sheep, camel, donkey, yak etc also contribute to human nutrition and health in different parts of world. These milks are source of staple traditional product and considered as delicacy in parts of Europe, UK, USA etc. The microbiota of raw milk and fermented milks, cheeses, made from raw milk is complex. These microorganisms have immense role in determining quality and safety of the subsequent product made from these milks as they may be responsible in spoilage and reducing shelf life, causing human health issues, also contribute to development of flavor and aroma formation, texture development, ripening cheese. Different factors like host, stage of lactation etc. affect the composition of microbiota present in the milks and methods like cultural and culture independent methods metagenomic analysis have been done to determine the microbial community present in the milk.

Introduction

Non- cow and non-buffalo milks such as milks from goat, sheep, camel, donkey, yaks etc. are one of the important sources of nutrition in different parts of the world. In Mongolia, the highlands of the Afghanistan and Pakistan, Himalayas in India, Nepal, and Bhutan, Tibetan Plateau and in the Mountains China yak milk is the only source of milk. Cheese made from sheep and goat milk are categorized as gourmet food and many times regarded as protected designation of origin (PDO) status. Camel milk is used for medicinal food and donkey milk is suitable for children, aged people due to its hypo allergenic properties. These milks and milk products like cheese, naturally fermented milks and yoghurt are staple traditional foods in different parts of the world.

Domestication of animals was followed by the provision of shelters for protection which also modified the climate to suit the species housed for improving the productivity and reproductive efficiency. Climate is the long term average condition of the meteorological variables in a given region. The climate is divided into macro climate and micro climate. Macro climate is the general large scale climatic conditions of the open atmosphere in a large area. Micro-climate is the climatic conditions directly surrounding the animal or the physical environment in the immediate vicinity of the animal. The environment includes all the combination of conditions under which the animal lives. The immediate variables that affect the production and reproduction of animals are its micro climatic variables. The animals have requirements of their own. The environment influences where and how animal lives. Domestication has resulted in man dictating where and how animal lives. Thus breeds of livestock evolved in temperate regions have been introduced into tropical area with high rainfall, humidity and temperatures. Homeotherms are a group of animals which maintain their deep body temperature essentially constant. All the domestic animals are homeotherms. In the case of an inert body, basic thermodynamic forces establishes an equilibrium in which the body attains the same temperature of the surrounding environment. The same law applies to homeothermic animals also. Therefore, these animals will have to make compensatory physiological and behavioural adjustments to keep a constant deep-body temperature. While digestion of food takes place in the body of animals, a portion of the energy in the feed is converted into heat. This metabolic heat plus the heat gained from the environment through conduction, convection and radiation results in excess heat gain to the animal, which has to be dissipated, if heat balance is to be maintained. For this the animal depends on various physiological and behavioural functions. This balancing act by which a constant normal core temperature is maintained is known as homeothermy. Heat production is regulated by hormonal secretions, changes in muscle tone, shivering and by voluntary muscular activity. Heat loss is controlled by vasodialatation, increasing the cutaneous circulation and evaporative loss. The animal reduces its feed intake as well as production, drink more water. In long term the hair coat becomes lighter with less insulation. The animal will also exhibit postural changes and behavioural adjustments. They will try to increase surface area, reduce physical activity and seek shade.

A farm microclimate refers to the specific climatic conditions of a small, localized area within a farm. These conditions can differ significantly from the broader regional climate due to various natural and man-made factors. Understanding and managing microclimates is crucial for optimizing crop growth, animal welfare, and overall farm productivity. Modern commercial dairy production requires a special approach to the microclimate on the farm. High quality milk and animal health depend on the conditions of their keeping. At the same time, farm for dairy production for the most part do not have the means to control and manage the microclimate, in contrast to poultry farm. When organizing the correct process of controlling the microclimate, a prerequisite is the presence of an automated system for collecting data. Generally animals adapt to a wide range of weather conditions although their growth and productivity varies with weather conditions. Buffaloes and cows form the main component in dairy industry. The extent to which these animals can adapt to different weather conditions is given below: Successful management of buffalo rearing will be incomplete without wellplanned and adequate housing facilities (Fig.10.1).
Improper planning in the arrangement of animal housing may result in management problems, increase in disease incidence, additional labour charges and hence decrease in the profit of the farmer. During erection of a house for dairy buffaloes, care should be taken to provide comfortable accommodation for individual animals. It is important to ensure:
• Proper sanitation
• Durability
• Abundant supply of clean water
• Arrangements for the production of clean milk under convenient and
economic conditions.
Buffaloes may be successfully housed under a wide variety of conditions, ranging from close confinement to little restrictions except at milking time. However, two types of farms are in general use.

Change in weather affects growth and development of plants. The extent of these effects depends upon the range or severity of change of weather. It is very much possible to change the weather in relatively small area to reap better harvest. Micro weather modification is defined as, “The manipulation of weather elements at increasing or decreasing the duration, intensity, quality etc., for desired effects at microlevel of crop under investigation”.

The climate near the ground can be managed partly by influencing the moisture status and temperature of the upper soil layers, e.g. by mulching and partly by action above the ground e.g. by shading or use of wind breaks.

There is an increased use of Glass houses and poly houses in commercial agriculture. The glass houses and poly houses provide a controlled environment for plants throughout the year. Some of the aspects of related to the advantages of Glass houses and poly houses are highlighted in the following text:
9.1. Glass houses
Glass houses are also referred as greenhouses. The glass prevents harmful ultraviolet radiations. The glass is transparent to solar radiations of wavelengths up to 300 nm and does not allow long-wave radiations to pass through it (Fig.9.1). Therefore, the Glass houses maintain higher temperature and high relative humidity during daytime as well as nighttime and offer the following advantages:
9.1.1. Controlled Environment: Glass houses facilitate regulation of temperature,
humidity, and light intensity, creating optimum environment for growing various plant species. This is especially beneficial for tropical and sub-tropical plants that require specific conditions to grow and survive.
9.1.2. Protection from Pests and Diseases: The enclosed glass house protects
plants from pests and diseases. The glass house also protects the plants from harsh weather conditions thereby minimizing risk of infestations and environmental stresses. Fig. 9.1: Microclimate management in Glass house
9.1.3. Extended Growing Season: By maintaining stable climate, glass houses
enable cultivation of plants that may not survive outdoors in certain climates thereby extending the growing season for sensitive species.
9.1.4. Research and Conservation: Botanical gardens often use glass houses for
research purposes, studying plant growth, genetics and breeding. The glass houses will also serve as a means for conserving rare or endangered plant species by providing stable environment for propagation. The advantage of glass houses is that the structure has long life span.
9.2. Poly houses
The poly houses are constructed using polythene material. The poly houses protect the plants from wind, cold weather, hail storms, extreme temperatures, insects and pests. The polythene house farming is a popular greenhouse technology due to its low cost of construction and maintenance. Generally, heat accumulation (70 to 75 per cent of solar energy) takes place inside the polyhouse. Solar radiation is allowed to pass through the polythene material and the long wave radiation cannot escape through polythene. The benefits of poly houses are:

There is growing demand for increasing fruit production as fruits are considered to be healthy, nutritious and easy to digest. Fruits are natural foods and have export potential as well as provide opportunities for increasing employment by establishing fruit processing industries. Some of the fruits can be grown around the year where as some fruits are of seasonal in nature. Usually, the fruit cultivation is undertaken by establishing orchards. In case of orchards, wrong decisions in planting may result in huge loss and therefore right method of planting is the key factor for establishing orchards.
The fruit crops are of three types depending on the adoptability to the climate of the region and are grouped as
• tropical fruits
• sub-tropical fruits
• temperate fruits
The microclimate of the orchards depends upon
• height of the plants/trees
• horizontal spread
• canopy architecture
• spacing/plant density
• age of plantation
• seasonal weather
15.1. Tropical Fruits
The tropical fruits require higher temperature throughout the year. The crops do not require low temperature for breaking dormancy and for flowering. The plants are ever green and grow throughout the year. There plants are well adopted to regions where the minimum temperatures are more than 10°C and very sensitive to frost. There are grown in tropical regions between 23°N to 23°S latitudes. The optimum maximum temperature for growth and development ranges from 30 to 37°C.
15.2. Sub-Tropical Fruits
The sub-tropical fruits perform better between temperate and tropical climates as the plant requires both high and low temperatures. Some of the fruit crops are green and some of those are deciduous. The temperate fruit crops are very sensitive to frost. The sub-tropical fruit plants break dormancy of flower buds

Microclimate under irrigated conditions and dryland conditions can differ significantly due to variations in water availability, which influences several environmental parameters such as temperature, humidity, soil moisture, and vegetation cover. The crops are grown both under irrigated and dryland / rainfed situations. The major difference between irrigated and dryland conditions is availability of water. In irrigated areas, the crops are regularly provided with water through irrigation at regular intervals. Under dryland situations, the water availability to the crops depends upon the rainfall and/or stored soil moisture. Under irrigated situations, there are two different possibilities as indicated below:
• vast stretch of irrigated areas
• isolated pockets of irrigated areas in predominantly dry areas. In dryland areas the following possibilities exist:
• humid and moist sub-humid areas where predominantly rice based cropping systems are adopted during rainy season
• per-humid areas where plantation crops and rice grown during rainy season.
• dry sub-humid areas with rice based cropping systems in low lands and finger millet, maize based cropping systems in upland areas
• semi-arid regions where kharif crops are grown during rainy season.
• rabi-crops grown under conserved moisture conditions during post rainy season.
• arid regions where pearl millet based cropping system are practiced during rainy season.
• hill agriculture
The microclimatic conditions are likely to vary between irrigated and rainfed conditions due to different agro-ecological settings. The comparative analyses of microclimatic variation under both conditions are given below:

Modifying microclimates in agriculture involves altering the local climate conditions surrounding crops or plants to create a more favorable environment for growth. This can be achieved through various techniques when the crops are subjected to weather related stresses.
14.1. To Mitigate Moisture Stress during Droughts
When the crops are under moisture stress, the principles involved are conservation of soil moisture and reduce the evapotranspiration from crops. The moisture conservation can be achieved by suppressing soil evaporation using mulches (Fig. 14.1). The evapotranspiration can be reduced using antitranspirants. Some antitranspirents close the stomata of the leaves to reduce evapotranspiration. Some anti-transpirants increase the reflectance of radiation from the crops, thereby reducing heat load on crops. When crops are grown under irrigation in isolated patches, micro shelter belts can be provided across the predominant wind direction to reduce the increased evapotranspiration from advection. Advection is phenomena of horizontal transport of heat due to strong hot and dry winds.

Modifying microclimates in agriculture involves altering the local climate conditions surrounding crops or plants to create a more favorable environment for growth. This can be achieved through various techniques when the crops are subjected to weather related stresses.
14.1. To Mitigate Moisture Stress during Droughts
When the crops are under moisture stress, the principles involved are conservation of soil moisture and reduce the evapotranspiration from crops. The moisture conservation can be achieved by suppressing soil evaporation using mulches (Fig. 14.1). The evapotranspiration can be reduced using anti transpirants. These are chemicals sprayed on crops. Some antitranspirents close the stomata of the leaves to reduce evapotranspiration. Some chemicals increase the reflectance of radiation from the crops, thereby reducing heat load on crops. When crops are grown under irrigation in isolated patches, micro shelter belts can be provided across the predominant wind direction to reduce the increased evapotranspiration from advection. Advection is phenomena of horizontal transport of heat due to strong hot and dry winds.

1. INTRODUCTION

Many food components are encapsulated and stabilized by nature inside plant cells, but, with the growth in use of functional ingredients and product fortification with vitamins, antioxidants and nature-identical synthetic compounds, there is a need to stabilize and protect these ingredients from the rigours of processing and degradation during storage.

Many food products whose development was thought to be technically unfeasible are possible today because of the wide availability of encapsulated ingredients. Such ingredients are products of a process that totally envelops the ingredient in a coating or ‘capsule’ thereby conferring many useful and otherwise unusual properties to the original ingredients.

Encapsulation is a technique that is applied to preserve and/or protect numerous ingredients. In the flavour industry, the encapsulation process is used chiefly to convert liquid flavour materials to free-flowing, dried powdered products. In a broad sense, encapsulation technology includes the coating of minute particles of ingredients (e.g., acidulants, fats, and flavours) as well as whole ingredients (raisins, nuts, and confectionery products) that may be accomplished by microencapsulation and macro-coating techniques, respectively.

Micronutrient deficiency

Micronutrient deficiencies are the cause for widespread health problems, especially in developing countries. The deficiencies in vitamin A, iron, and iodine have been identified as the greatest concern, as they affect over one third of the world’s population (WHO, 1995). In addition, these micronutrients interact with each other, i.e., synergistic effects between iodine deficiency disorder (IDD) and iron deficiency anemia (IDA), or between vitamin A deficiency (VAD) and IDA to deepen their negative impacts (Lonnerdal, 2004; Lynch, 1997; Zimmermann et al., 2004). Deficiencies typically coexist in children in developing countries (Zimmermann et al., 2000).

70% of people in India do not consume enough micronutrients such as vitamins and minerals. About 70% of pre-school children suffer from anaemia caused by iron deficiency and 57% of preschool children have sub–clinical Vitamin A deficiency. Neural Tube Defects (NTDs) are the most common congenital malformation with an incidence that varies between 0.5-8/1000 births. It is estimated that 50-70% of these birth defects are preventable. One of the major causes is deficiency of folic acid. Thus, micronutrient deficiency also known as “hidden hunger”, is a serious health risk. Unfortunately, those who are economically disadvantaged do not have access to safe and nutritious food. Others either do not consume a balanced diet or lack variety in the diet because of which they do not get adequate micronutrients. Often, there is considerable loss of nutrients during the processing of food.

Introduction The Indian culinary world may have just recently embraced the concept of edible flowers, but they have been a part of traditional Indian cuisines since the beginning. Flowers have been used in human diets and gourmet preparations for thousands of years (Fernandes et al., 2020). However, due to increased consumer knowledge about the effects of nutrition on human health, there is a growing trend in utilizing flowers for edible purposes (Chatzopoulou et al., 2020). Edible flowers were used as a relish and flavour enhancer in many savoury and sweet meals in ancient Rome and Greece. In China’s ancient texts and classics, the words and phrases regarding edible blossoms were also recorded by Zhao et al. (2017). Edible flowers come in a wide variety of colors and cooking ways in different nations. Flowers, such as Osmanthus fragrans Lour and Flos Sophorae, have been employed as basic ingredients in a range of Chinese cuisines (Cunningham, 2015). The people of Rome used flowers in cooking. They make salads using violets and roses and sauces using lavenders. Flowers from pumpkin and squash plants have long been used as ingredients in the United States. People consume aromatic flower buds and unopened blossoms in El Salvador and Honduras. Blossoms are frequently used to garnish food at aristocratic banquets and feasts across Europe. Dandelion (Taraxacum officinale) flowers are also added to beverages and salads in many parts of the world.

Introduction

Encapsulation may be defined as a process to entrap one substance (active agent) within another substance (wall material). The encapsulated substance, except active agent, can be called the core, fill, active, internal or payload phase. The substance that is encapsulating is often called the coating, membrane, shell, capsule, carrier material, external phase, or matrix. In the food industry, encapsulation process can be applied for a variety of reasons. Encapsulation is a useful tool to improve delivery of bioactive molecules (e.g. antioxidants, minerals, vitamins, phytosterols, lutein, fatty acids, lycopene) and living cells  (e.g. probiotics) into foods [1]. In most cases, encapsulation refers to a technology in which the bioactive components are completely enveloped, covered and protected by a physical barrier, without any protrusion of the bioactive components. Also, encapsulation has been defined as a technology of packaging solids, liquids, or gaseous materials in small capsules that release their contents at controlled rates over prolonged periods and under specific conditions. Produced particles usually have diameters of a few nm to a few mm.

ABSTRACT

Wood apple is a hardy tree grown in arid and semiarid regions of the country. It is generally propagated through seeds. The traditional methods like budding and inarch grafting require 9 to 12 months for the root stock to come buddable size and thus 1½ to 2 years to become ready for transplanting. The present study was initiated to prepare a grafts within eight months by adopting the micrografting technique. The seeds were sown in the month of April in polybags filled with FYM, sand and soil in equal proportions with a pinch of blitox. The micrografting was done on 1½, 2, 2½ and 3 month old seedling root stock having a diameter of 0.13 to 0.15 cm, 0.17 to 0.19 cm, 0.20 to 0.22 cm and 0.23 to 0.26 cm, respectively. The seedling root stocks were decapitated with the surgical blade and 1 to 2 cm deep split was made. The scion micro bud (1 to 2 cm length and 1 to 2 mm width) of previous season’s growth was inserted in the split. The micropipette cap (0-200 μl) was inserted on the grafted portion. After sprouting of the micro bud, the micro pipette cap was removed. The study revealed that, micro bud grafting success was significantly influenced by the root stock age. Early bud take was observed when the micrografting was done on 2½ month (10.73 days) and 3-month (11.00 days) old root stock. The percent bud take on 3-month old root stock was significantly higher (99.33 per cent) than the rest of root stocks. Micrografting done on 3-month old seedling root stocks in June-July is suggested for quick multiplication of woodapple.

Purpose of Growing Microgreens in Space Farming

Microgreens are a perfect dietary ingredient in space because of their special benefits, which have been explained in earlier chapters. In an atmosphere of a spaceship with limited water and electrical power for artificial illumination, their comparatively low light and water consumption are advantageous. Furthermore, because spaceships and shelters have limited capacity, microgreens' tiny size might be advantageous. Given the right sanitization procedures, microgreens may be harvested fresh and consumed right away. Their striking colour and robust flavour may also improve meal presentation and pique astronauts' appetites. 

The science dealing with the measurement of size of any microscopically visible microorganism is known as micrometry which is based on the principle of physics. Before measuring a cell, the diameter of the microscopic field must be established by means of optic devices, namely an ocular micrometer and a stage micrometer.

a)Ocular micrometer : It is a circular disc that is placed in the eyepiece. The disc is graduated in to several small divisions marked from 0 to 100.It is placed inside the eyepiece of the microscope. The distance varies according to the objective of the microscope which can be easily determined by using a stage micrometer.

b)Stage micrometer : It is a glass slide graduated in 1 mm. Again 1mm is divided into 10 large divisions and 100 small divisions (10 x 10 = 100 divisions). These divisions are equally placed therefore 1 small division is equal to 0.01 mm or 10 μm.

The induction of mutations in polygenes controlling quantitative characters can be detected by the estimation of mean and variance of progenies from normal looking mutagen treated populations. Induction of micromutations in different crop plants have been reviewed by various investigators like Gregory (1955, 1968) in peanut, Rawlings et al. (1958) in soybean, Oka et al. (1985) in rice, Brock and Latter (1961) in Trifolium, Borojevic (1966) and Scossiroli (1966) in wheat, Gaul (1961a, 1966), Astveit (1966) in barley and Brock (1967) in Arabidopsis.

Though more reliable results can be obtained from the study of quantitative variation in the advanced generations than in M₂ (Aastveit, 1968, and Scossiroli, 1977), an estimation of the extent of induced genetic variability in quantitative traits in M₂ itself will be valuable in providing information for future selection programme. It was therefore considered worthwhile to study the shift of mean values and to gather information on induced genotypic variance heritability and genetic advance for different quantitative traits from families of M₁ from different mutagenic treatments.

12.1 Introduction

Micronization is a size reduction in which particles are reduced down to micrometer resulting in particle-size distribution is less than 10 microns. Acceleration of particles has been involved for particle-to-particle impact or impact against a solid surface. Micron technology is an emerging technology which has a great potential in nutraceuticals and functional foods. By increasing the surface area per unit mass, compared with larger-sized particles of the same chemistry, tiny particles are made more biologically active. A lot of attention has been gained by micronization in food research and development. Functional properties, surface areas and structures gets altered by reduction in particle sizes of different materials (e.g., metal salts, metal oxides, chitosan and organic compounds) by micronization or nanotechnology to micro- or nano-sizes and bring some new applications in the academic world as well as in food industry.

They absorb a large concentration (10-40 wt %) of C0₂ that either swells the polymer or melts it at a temperature below (10 to 50 °C) it’s melting/ glass transition temperature hence, this technique is useful for micronization of especially for polymers. Active substrate(s) in a polymer or other carrier substance can be used with suspensions for micronization process. In manufacturing advanced pharmaceuticals, coating materials, micro sensors, polymers and many other chemicals particle design has been gaining importance. Formulation homogeneity and control particle size can be improved by micronization. Moreover, bioavailability of poorly soluble APIs (active pharmaceutical ingredient) by increasing particle surface area and accelerating dissolution rates can also be improved. Because of the high impact velocities possible as a result of particle acceleration in a fast gas stream, fluid energy mills are used for micronization. Particle velocities in a jet mill are in the range of 300 to 500 meters per second, compared to 50 to 150 meters per second in a mechanical impact mill, in many industrial fields like food technology, pharmaceuticals, catalysts, pigments, and biopolymers, for example, are some categories of products that can be used as micro-sized particles, micronized powders are of great interest. High-temperature reactions that require high energies, on jet milling that is characterized by low efficiencies and mechanical stress, and on liquid solvents precipitation that has a poor control on particle size and can pollute the product comes under the traditional techniques for producing micronic powders. Generally, the control of the powder size and the span of its distribution are still very approximate. In recent years, many supercritical fluids-based techniques have been developed for the production of micronic and nanometric particles. Some particular properties of gases at supercritical conditions such as enhanced solubilization modulation and its power, large diffusivities, organic solvent reduced operation, and the connected possibility of controlling powder size and distribution resulted from this process. Important characteristics of powders like particle size and size distribution have significant effects on dissolution properties, flowability and release kinetics. Therefore, particle engineering is the most important step during processing of powdered foods. Lower micrometer range and sizes are needed for many applications particles with special requirements. Processes like jet milling, pearl milling or high pressure homogenization are used for micronization.

Genotoxicity potential of any environmental pollutants can be investigated using the micronucleus (MN) test. It is among the most sensitive DNA damage indicators and it has been applied to several organisms and tissues for evaluation of environmental contaminants (Lemos et al., 2011). Micronuclei (MN) assay is more rapid and simpler than chromosomal analysis (Gandhi et al., 2003). Compared to the chromosome aberrations, the final result is relatively easily scored and thus requires less time to make an assessment of the clastogenicity of a chemical (Garriott et al. 2002). An in vitro MN assay can detect the clastogens and aneugens as well as mitotic delay, apoptosis, chromosome breakage, chromosome loss and non-disjunction (Corvi et al., 2008). Although, micronuclei constitute well-characterized biomarkers of chromosomal damage (Salazar et al. 2009) but in vitro MN test does not provide information on the origin of micronuclei (Corvi et al., 2008).

Experimental Procedure

Micronuclei assay is carried out in PMNC and splenocytes as per method of Hayashi et al. (1983).

Equipment

1. Adjustable pipette.
2. 20-ml glass beaker.
3. Atomic Absorption Spectrophotometer.

Micronutrients are those elements essential for green plants but required in very small quantity for their growth and development. There are altogether eight micronutrient elements in soil consisting of iron, manganese, zinc, copper, boron, molybdenum and chlorine with the recent addition of nickel. These together with large number of other elements usually present in plants with small concentrations are formed as trace elements. Another element, cobalt is known to be required for microorganisms concerned mainly with nitrogen fixation in legumes affects indirectly the growth of many higher plants, thus, may be considered to be included in the list of essential micronutrient element. Similarly, Vanadium and sodium although present as beneficiary elements for plant growth may also have the possibilities to be enlisted into this group of elements.

Abstract

Micronutrient (vitamin and mineral) deficiencies affect more than 2 billion people worldwide and are especially prevalent in developing countries including India. Conditions due to vitamin mineral deficiencies account for 7.3 percent of the global disease burden.Iron deficiency (anemia), vitamin A and iodine deficiency disorders continue to be a grim public health problem. Thus, elimination of vitamin and mineral deficiencies is essential to improve the overall health of the masses as well as to sustain economic growth and national development. Food fortification is an effective intervention to deliver vitamin and mineral rich foods to large populations. In addition to the prevention of vitamin and mineral deficiencies, food fortification is an effective measure to raise vitamin and mineral levels by moving the population towards consuming recommended dietary allowances for most micronutrients-making it a long–term and a sustainable strategy. India is the largest producer of milk in the world with 146.3 million tonnes and the consumption rate of milk and milk products by all age groups of people are high.Therefore, fortification of milk with mineral and vitamins could be a safe and effective strategy to fight these micronutrient deficiencies.

Micronutrients are required in small quantities but are essential for normal plant growth and crop productivity. Their availability in irrigated soils can vary considerably because of changes in soil pH, moisture conditions, organic matter, texture and interactions with other nutrients. This chapter introduces the concepts of micronutrient deficiency and toxicity and discusses critical limits used for evaluating micronutrient status. Particular emphasis is placed on boron and zinc. Boron content, deficiency in Indian soils, availability and leaching are examined, together with the influence of soil texture, pH and moisture. Boron indicator plants, correction of deficiency, sources, crop response and frequency of application are also discussed. Interactions between boron and other nutrients receive attention. The chapter then considers zinc content and zinc deficiency in soils and examines the influence of pH, phosphate level, organic matter and adsorption by clay minerals on zinc availability. Methods, timing and rates of zinc application and crop responses are presented to support effective micronutrient management.

ZINC (Zn)

Chandler et al., (1932) deduced the requirement of zinc by plants while working solution for little leaf or “rosette” on peach. Zinc plays significant role in assimilation of NO₃ and for synthesis of tryptophan. Involved in biosynthesis of indole acetic acid which is responsible for f lowering and fruiting, it is an activator of several enzymes (triphosphate dehydrogenase and tryptophan synthetase), involved in photosynthesis and nitrogen metabolism.

Deficiency results in poor growth of the terminal bud. Decrease in stem length resulting in resetting and whorling of leaves. Zinc deficiency disorder in rice is called khaira. Common when zinc availability is < 0.7 ppm. White bud in maize and malformation of fruits, reduction in water uptake. Interveinal chlorosis often with necrosis and pigmentation and reduced leaf size in broad leaved crops known as little leaf and malformation of leaves.

The crops which are known to respond for zinc application are maize, rice, soyabean, castor, onion, barley, wheat, potato, sorghum and cotton

Iron (Fe), zinc (Zn), copper (Cu), manganese (Mn), nickel (Ni), boron (B), molybdenum (Mo) and chloride (Cl) elements are known as micronutrients. The micronutrients are also called as trace elements or minor elements as they are required very small quantities by plants. The elements Fe, Zn, Cu, Mn and Ni are known as micronutrient cations and B, Mo and Cl are known as micronutrient anions and they behave accordingly in soils. Among these elements, Fe content in soil as well as plant is the highest and sometimes higher than phosphorus (P) and sulphur (S). In plant, the concentration of micronutrients often found up to 100 mg kg^-1, except that of Fe and Mn which may go up to 500 mg kg^-1 (dry weight basis). Another element, cobalt (Co) is also regarded to be essential for the growth of certain higher plants and animals, and likely to be included in the list of micronutrients. The importance of micronutrients has been realized during the past four decades when micronutrient deficiencies were observed in most of the soils in our country, where intensive agriculture is practiced.

25.1 Determination of Available Micronutrient cations (Zn, Cu, Fe and Mn) in Soil

The available micronutrient cations (Zn, Cu, Fe and Mn) can be estimated in a single extraction with diethylene triamine pentaacetic acid (DTPA) as proposed by Lindsay and Norvell (1978). DTPA has the excellent property to combine with free metal ions in the solution forming soluble complexes. The stability constants of metal-DTPA complexes make DTPA as a most suitable extractant for simultaneous complex formation with Zn, Cu, Fe and Mn. In calcareous soil DTPAextractant may result overestimation due to excess dissolution of CaCO₃, causingrelease of occluded micronutrient cations which are not plant available. To avoid this excessive dissolution of CaCO₃, DTPA is buffered at pH 7.3 using triethanol amine (TEA). At this pH major part (3/4^th) of TEA is present as HTEA⁺ (protonation) and exchanges for Ca and Mg ion from the soil exchange site. This increases concentration of Ca and Mg in the solution phase and suppresses dissolution of CaCO₃. The DTPA has the capacity to form complex with each of the micronutrient cations 10 times of its atomic weight and it ranges from 550 to 650 ppm depending on the micronutrient cation.

The amount of cation in the extract is determined on an atomic absorption spectrophotometer (AAS). The experimental condition such as shaking time, DTPA concentration, pH and temperature during shaking influence the amount of Zn, Cu, Fe and Mn extracted. Increase in shaking time and temperature markedly influence the extractability of these cations.