eChapters

I. FILL UPS

1. Rapid and uniform production of healthy seedling and stand establishment under a wide range of field condition is considered as _____.
2. The sum of those properties of seed which determine the potential level of activity and performance of the seed lot is called _____.
3. Vigour index = _____.

I. FILL UPS

1. The seed colour of cv COH₂ is _____.
2. The special appendage present in castor is called _____.
3. Modified phenol test was identified by _____ for pearl millet hybrids.
4. _____ test is for the varietal identification of sorghum.

I. FILL UPS

1. ISTA was founded in _____.
2. ISTA secretariat is located at _____.
3. _____ was founded with the aim to develop and publish standard procedures in the field of seed testing.
4. _____ is one of the leading international journals featuring papers and articles on seed quality and physiology published by ISTA.
5. The technical committees are made up of _____ number of members.

1. VARIETAL SEED PRODUCTION

3 m : Rice, soybean

5 m : Blackgram, greengram, cowpea, field lab lab lab lab

5-10 m : Groundnut

25 m : Tomato

60% - Bottlegourd, pumpkin, bittergourd, watermelon

65% - Cotton varieties, bhendi

I. FILL UPS

1. _____ is the maintenance of high seed germination and vigour from harvest until planting.
2. _____ is important to get adequate plant stand in addition to healthy and vigours plants.
3. _____ seeds can be dried to 6-10% moisture depending upon the species.
4. _____ seeds cannot be dried below 30-35% moisture and should be maintained at this temperature.

I. FILL UPS

1. _____ is defined as deteriorative mechanism occurring with time that increase the seeds vulnerability and decrease ability to survive.
2. Lettuce seeds develop red necrotic lesions in cotyledons known as _____.
3. _____ morphological changes occur in ground nut due to deterioration.

I. FILL UPS

1. _____ refers to the application of pesticides to seeds before sowing or storage to protect the seeds.
2. The chemical gases as fumes are used to control the pests in seed lots is called as _____.
3. The treatments given to the seeds prior to or during storage to protect the seed are called _____ treatment.

I. FILL UPS

1. _____ are capable of reducing the age induced damages and restoring the seed vigour by controlling free radical reactions.
2. _____ is the process of soaking the low and medium vigour seeds in water with or without adding chemicals to raise seed moisture and drying back for safe storage of seeds.
3. _____ treatment is similar to the moisture equilibration treatment.

I. FILL UPS

1. _____ is a collection of genetic resources for an organism.
2. The conservation of species in their natural habitats is called _____.
3. _____ is the preservation of components of biological diversity outside their natural habitats.
4. _____ is a type of gene bank that stores seeds as a source for planting in case seed reserves elsewhere are destroyed.

I. FILL UPS

1. The area of science that studies the relationship between pathogens and seeds is _____.
2. The diseases that are caused by fungal pathogens in residues and on the soil surface are defined as _____.
3. The establishment of a pathogens in any part of the seed is referred as _____.

I. FILL UPS

1. _____ refers to the health status of a seed.
2. A group of fungi that infects developing seeds on the plant in the field, but before it is threshed is called as _____.
3. _____ fungi invade seeds at (or) after harvest.
4. _____ method is used particularly for smut and bunt fungi in gramineous host.
5. _____ method is used for detection of karnal bunt of wheat.

I. FILL UPS

1. _____ is the most important primary pests of cereals.
2. _____ causes serious damage in maize cob.
3. _____ is the field pest of pulses.
4. _____ feeds on already damaged.

I. FILL UPS

1. _____ are also called ed-worms.
2. _____ nematode causes discolouration in groundnut.
3. _____ in rice is caused by Aphelenchoides besseyi.
4. The ear cockle disease is caused _____.

I. FILL UPS

1. RCA stands for _____.
2. Expert standing committee was set up in _____.
3. In _____year, All India Co-ordinated maize improvement programme was started.
4. First maize hybrid was released in the year _____.
5. All India co-ordinated bajra and sorghum improvement programme was started in _____.
6. First sorghum hybrid was released in the year _____.

I. FILL UPS

1. _____ refers to the actual acquisition and selling packed seeds, intermediate storage delivery and sales promotional activities.
2. _____ entails using marketing information for the purpose of planning.
3. _____ is one of the major channel through which bulk of paddy seeds, pulses seeds and oil seeds are marketed in the state.

Soil is a mass of large variability and thus its sampling is the most challenging problem for any soil analyst. Practically, soil sampling is a two step process which includes (i) collection of soil from homogeneous unit and (ii) processing which in turn includes drying, grinding, sieving, mixing, partitioning and storing.

1.1. Sources of Error in Soil Chemical Analysis

Different sources of error involved starting from soil sampling to chemical analysis of a sample can be divided into three main groups:

1. Sampling error : This error results from variability among the different samples drawn from same soil unit with respect to the objective of sampling.
2. Sub-sampling error : This error is due to variability introduced among sub samples of the same soil sample.
3. Analytical error : This error introduced due to variability from one chemical determination to another on same sub sample.

2.1. Particle Size Distribution Analysis

Soil is composed of particles of varying size and shape. The expression of the proportion of the different size particles is termed as ‘soil texture’. It is one of the most important basic characters being little changed by cultivation or other practices. Particles are arbitrarily distinguished into following groups on the basis of their diameters.

3.1. Determination of Bulk Density of Soil

3.1.1. Determination of Bulk Density of an Undisturbed Soil

Bulk density of soil is expressed as the ratio of the mass (weight) of soil particle to their total volume including the pore space between the soil particles. Alternately, it is the weight of unit volume of dry soil. It is usually expressed in the unit of gram per cubic centimeter (g/cc) or mega gram per cubic meter (Mg/m³). In fine textured soil bulk density varies from 1.00 to 1.60 g/cc, whereas in coarse textured soil from 1.20 to 1.80 g/cc.

In natural condition primary soil particles cohere to each other to form a cluster or an aggregate through the cementing action of various agents like organic matter, oxides of iron and aluminium, carbonates, etc. Aggregate analysis tells one about the structural status, pore geometry which in turn influences the movement of air and water in soil, amount of water stable secondary particles (aggregate) as well as the extent of finer particles aggregated to the coarser particles and the erodibility status of surface soil against wind and water.

Methods of Analysis

Among the several methods of aggregate analysis the commonly used methods practiced in agriculture and related fields are wet sieving and dry sieving method of aggregate analysis.

5.1. Determination of Soil Moisture

5.1.1. Determination of Soil Moisture Content by Gravimetric Method (Direct method)

Traditionally water content in soil is expressed as the ratio of the weight of water present in the soil to the weight of dry soil. When this ratio is multiplied by 100, it becomes the percentage of water in the soil sample on dry weight basis.

6.1. Determination of Hydraulic Conductivity of Saturated Soil: Laboratory Methods

Hydraulic conductivity of a saturated soil indicates the ease with which water is transmitted through the soil pores. If a constant water head (h) is maintained on a saturated soil column of length (L) and the volume of water (V) percolating per unit time (t) through per unit cross sectional area (A) to the other end, then according to Darcy’s Law the rate of flow of liquid or flux (q) is proportional to the hydraulic gradient (ΔH/L) across the length of soil column.

Soil consistency is a term used to designate the manifestation of different physical forces acting within the soil at various moisture levels. The consistency limits, also known as ‘Atterberg Limits’ (Atterberg, 1911; 12) are defined by the water content of the soil to create specified degree of consistency. These limits are – (i) Liquid limit or upper plastic limit, (ii) Plastic limit or lower plastic limit and (iii) Sticky limit.

7.1. Determination of Liquid Limit or Upper Plastic Limit

Equipments and Materials

Liquid limit device (Casagrande, 1932) and accessories, spatula, dish, oven, moisture box, balance, desiccator

8.1. Law of Mass Action

Gulberg and Waage, the two Norwegian chemists in the year 1864 stated the law of mass action in this form: ‘The velocity of any chemical reaction at any instant at a given temperature is proportional to the active mass of each of the reactants at that instant present in the system, the active mass in a homogeneous system is defined as the number of gram molecule of the substance present per unit volume i.e., the molar volume’.

Mathematical Formulation of the Law of Mass Action

Let us take a simple case of a reversible reaction at constant temperature represented by the equation:

9.1. Balance and Weighing

9.1.1. Principle of Functioning of a Balance

It is one of the important tools used in the laboratory and one should have thorough knowledge about its assembly, use and care, otherwise it may be the initial step for introducing error in any physical or chemical analysis. Every balance has its maximum load limit and sensitivity depending upon its construction.

Essentially balance may be regarded as a rigid beam, BC having a central fulcrum, O and two arms of equal length, d₁, d₂ (Fig.9.1). The both ends of beam have prism edges upon which the balance pans are suspended by means of suitable suspension.

10.1. Determination of Soil pH

The soil pH value is the measure of hydrogen or hydroxyl ion activity in the soil solution and it indicates whether the soil is acidic, neutral or alkaline in reaction. The pH is the most important property of soil as it controls the availability of plant nutrients, microbial activity and physical condition of soil. Since crop growth is affected both under very low (strongly acidic) and very high (strongly alkaline) soil pH, reclamation of these soils are necessary. Soil pH in fact indicates the extent of active acidity (activity of hydrogen ion in soil solution) of soil. Depending upon the purpose of measurement and soil condition, soil pH is measured in several soil-water or soil-salt solution ratios. The saturated paste is used for identifying specific soil problems like degree of acidity or alkalinity. For making fertilizer recommendation, 1: 2 soil-water suspension is generally adopted. To mask the variability in salt content of the soil, the pH is measured in soil-CaCl₂ suspension (1:2 soil-0.1 M CaCl₂ solution). The soil pH value is independent of dilution over a wide range of soil-salt solution ratio, thus more reproducible than those obtained with soil-water suspension.

11.1. Determination of Electrical Conductivity of Soil Solution

The conductivity or more precisely the specific conductance of a soil at a given soil-water ratio is the reciprocal of the specific resistance offered by the solution at 25ºC between the electrodes of 1 sq cm cross section kept 1 cm apart. Thus, the electrical conductivity of any solution depends on the amount of soluble salt present in it. Knowledge on the extent of salinity is important for management of saline soil including the choice of the crop suitable for that soil. Soluble salt content in saturation extract is more reliable index of salinity level than in soil: water ratio of 1: 2 or 1: 2.5 because it simulates the extent of salinity experienced by crop in field moisture condition.

Salinity class of soil is based on the electrical conductivity (EC) of saturation extract at 25ºC. However, EC of water extract from 1:2 soil-water suspension can be transformed into the EC of saturation extract following the formula (except for soil containing gypsum).

Carbon may present in soil in four different forms:

1. Carbonates: Mainly as CaCO₃ and MgCO₃, active CO₃^2- and HCO₃^- ions and gaseous CO₂.
2. Highly condensed elemental organic form: Charcoal, graphite.
3. Completely decomposed resistant organic residues: Humus.
4. Undecomposed and partially decomposed organic residues.

13.1 Exchange Capacity

Soil colloidal particles carry both negative and positive charges on their surface which attract and hold equivalent amount of oppositely charged ions to their surface. The total number of negative charges present on a given mass of soil or capacity of a given mass of soil to exchange cations or total number of cation held by a given mass of soil is termed as cation exchange capacity (CEC). Similarly, the capacity of a soil to retain anions is known as anion exchange capacity (AEC). The ion exchange capacity of a soil depends upon the type and amount of colloidal particle (clay and organic matter) present in the soil. Ion exchange capacity (CEC / AEC) is expressed as milliequivalent ion (cation / anion, respectively) per 100 g of soil (meq / 100g). It is also expressed as centimoles of charge (positive / negative) per kg of soil [cmol (±) / kg]. Meq / 100g = cmol (±) / kg of soil.

14.1. Determination of Total Nitrogen in Soil (Modified Kjeldahl Method)

Nitrogen mostly present in soil in organic form. Relatively small amount of nitrogen usually occur in ammonium and nitrate form, the available form. The Kjeldahl method of total N determination includes both organic and ammonium form and with modification nitrate form of N can also be included.

Phosphorus in soil present both in inorganic form and organic form. The inorganic P can be divided into different pools. The major active inorganic forms are: P bound to aluminium (Al-P), iron (Fe-P), calcium (Ca-P) and silicate minerals and relatively less active forms are occluded and reductant soluble forms of P. On the other hand the principal organic P compounds present in soil are (i) inositol phosphate, (ii) phospholipids, (iii) nucleic acid and other unidentified esters and phosphoproteins.

15.1. Determination of Available Soil P

The availability of soil P to plant varies greatly depending upon the reaction, minerological composition and amount of the soil colloid. Very little P is present in the soil solution except in recently fertilized or sodic soils. The type of phosphate ions present in the soil solution depends on the soil pH. In soils of neutral to slightly alkaline pH, HPO₄^2- ion is the dominant form. In slightly or moderately acidic soils, both H₂PO₄^- and HPO₄^2- ions prevail. At strongly acidic soil H₂PO₄^- ion tends to dominate, while above pH 9.0, the PO₄^3- ion becomes more important than H₂PO₄^-.

16.1. Forms of Soil K

Ignoring potassium (K) in soil organism, total K in soil may be classified as (i) water soluble K, (ii) readily exchangeable K (exchangeable K), (iii) slowly exchangeable K (non- exchangeable or fixed K) and (iv) mineral or lattice K. The different forms are in dynamic equilibrium with one another.

Sulphur (S) occurs in soil in both organic and inorganic forms. Inorganic S fraction may occur as sulphate (SO₄^2-) and compounds of lower oxidation state such as sulphide (S^2-), polysulphide (S_n^2-), thiosulphate (S₂O₃^2-) and elemental sulphur (S⁰). In well drained soils inorganic S usually present as sulphate. Under anaerobic condition (reduced or waterlogged soil) inorganic S mainly occur as sulphide and under extreme condition as elemental S form. Estimation of S carried out in two steps:

18.1. 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 DTPA extractant may result overestimation due to excess dissolution of CaCO_3, thus releases 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 complex 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.

19.1. Plant Available Fraction of Nickel, Cadmium, Lead and Chromium

The DTPA method was originally developed to extract Mn, Cu, Fe and Zn from slightly acidic to alkaline soils (Lindsay and Norvell, 1978), but in some cases it can be used for other metals also such as Nickel (Ni), Cadmium (Cd), Lead (Pb) and Chromium (Cr). Among them Ni is considered as an essential micronutrient. The DTPA is used to extract soil metals by forming chelates with free metals in solution, which lowers their ionic activities so that additional quantities of metal are released from the soil until equilibrium is attained. Triehanolamine (TEA) is used to buffer the extracting solution at pH 7.3 in an attempt to optimize the extraction of various metals. Calcium chloride is included in the extracting solution to minimize dissolution of CaCO₃.

Crop production broadly depends on the fertility of the soil where a crop is raised. There are several factors like the kind and quality of seed, climate, water supply, and plant protection measures etc. that affect the crop production. Among these factors, the fertility status of the soil largely determines the ultimate yield even if all these factors are optimum for crop production. A clear distinction should be made between soil fertility and soil productivity. Soil fertility deals with the inherent capacity of soil to provide nutrients in adequate amounts and in proper balance, for the growth of specified plants when other growth factors such as light, water and temperature, and the physical condition of the soil are favourable. Soil productivity is concerned with the capability of soil to produce a specified plant or plant parts or a sequence of plants under well defined and specified systems of management inputs and environmental conditions, viz. climatic conditions. It does not mean that a fertile soil is always productive. A fertile soil, under a bad management system, may be unproductive for a crop. In this book, plant nutrient elements and their available forms, functions and deficiency symptoms are briefly described for the better understanding of soil testing and fertilizer recommendation.

Soil testing is a useful tool that can help to ensure the efficient use of applied plant nutrients. Soil tests provide a means for assessing the fertility status of a soil, but soil tests do not provide a direct measure of the actual quantity of plant available nutrients in the soil. Instead, soil tests measure the quantity of a nutrient element that is extractable from a soil by a particular chemical extracting solution. The measured quantity of extractable nutrient in a soil is then used to predict the crop yield response to application of the nutrient as fertilizer, manure, or other amendment. As soil test levels increase for a particular nutrient, the expected crop yield response to additions of that nutrient decreases. A soil-testing programme has four phases as follows:

1.Collection of soil samples,

2.Chemical analysis of soil samples,

3.Calibration and interpretation of the results of chemical analysis, and

4.Nutrient/Fertilizer Recommendation.

3.1 Important Soil Physical Properties

3.1.1 Analysis of Soil Texture

Soil texture refers to the relative proportions of sand, silt, and clay on weight basis. Soil texture was recognized from very early times by experienced farmers from the feel of moist soil placed between the thumb and forefinger. The size groups arbitrarily classified by the International Society of Soil Science (ISSS) into clay (< 0.002 mm), silt (0.002 0.02 mm), fine sand (0.02-0.2 mm), and coarse sand (0.2 2.0 mm). Each soil textural name specifies the weight percent of each fraction falls within certain defined limits. The determination of the percentage of the soil separate present in a sample is called particle-size analysis.

Each type of particle present makes its contribution to the nature of the soil as a whole. Sandy soils are usually quite permeable to air, water, and roots, but they have two important limitations. One is their relatively low water-holding capacity; the second is that they are poor storehouses for plant nutrients. These limitations of sandy soils can, of course, be overcome if both fertilizer and irrigation water are available, but the costs are large.

Clay not only have a large surface area per gram, it also has electrically charged particles. These charges give clay the capacity to attract plant nutrient ions to its surface in forms available to plants, but sand lacks this capacity. Clay holds much more water than sands because they have a large surface area to be coated with water. One important problem with clay soils is their stickiness. When wet, they stick to ploughs, boots, or whatever they contact. Loam and silt loam soils are highly desirable for most uses. They have enough clay to store adequate amount of water and plant nutrients for optimum plant growth but not so much clay as to cause poor aeration or to make working with them difficult.

4.1 Sampling and Preparation for Analysis

The determination of nutritional need of crops is an important aspect of nutrient management of any plant analysis programme. The need of fruit plants for mineral nutrients differ from those of annual crop species in a number of ways, many of which are related to the perennial nature of tree crops. In perennial tree crops, there is a need to supply nutrients both for ultimate fruit production, the fruits and the vegetative organs, which persist from year to year. The need for leaf analysis in perennial horticultural crops and forest trees has proved its superiority over soil diagnostic methods. This is essentially because of their deeper root system and the fact that nutrients supplied in one year may have its effect on both the nutrition and crop production in following years. However, it is largely being used not as an alternative method to soil testing, but as a supplement to soil testing. Results of foliar analysis are usually interpreted using the critical nutrient level (CNL) approach. Accurate interpretation of foliar analysis using the CNL approach is possible only when sampling is restricted to the same growth stage at which standard reference values have been established (Beaufils, 1971, 1973). The general purposes of plant analyses are:

5.1 Sampling

There are different sources of water such as rain, streams, canals, lakes, tanks, ponds, large reservoirs, shallow and deep wells, shallow and deep tube wells, as well as sewage effluents and sea water. The composition of the different sources of water vary with the season, rate of flow, the extent of effluents from the industrial units and sewage effluents from the municipal area during rainy season, the river tank and pond water becomes salty and muddy due to soil erosion. The depth of ground water also varies with the seasons. The sources of water available to the farmer for irrigation of crops are generally few such as canal, shallow and deep wells, pumping sets, tube wells and runoff water collected in excavations along roads, natural drains and adjoining areas under impeded drainage. The composition of water also varies with the season. Whatever may be sources of water, the water sample is taken along with the soil sample to soil testing laboratory for its analysis by way of assessing the suitability of water for irrigation.

For drawing maximum benefit the samples taken be representative of the water in bulk and it should be collected in a clean vessel. One to three litres capacity plastic bottles duly washed with a detergent are satisfactory. However, before filling with water samples the bottles must be rinsed with water samples three times. The information such as farmers name, owner of pumping sets, date and month of sampling depth of ground water, crops and soils being irrigated, any specific agricultural or human problems encountered to be briefly recorded along with the name of village, block, tehsil and district. The water sample should be properly labeled and submitted to soil testing laboratory for its analysis.

India is recovering from the euphoria of the Green Revolution and battling the residual effects of the extensively used chemical fertilizers and pesticides in the country’s soils. The decade from 1980 to 1990 alone saw the area under pesticides in India, increased a whopping 20-fold, from six million hectares to 125 million hectares. After a high annual consumption of nearly 75000 MT reached in the early ’90s, interventions in the form of Integrated Pest Management (IPM) practices have only now started to show a declining trend in the use of pesticides in India. Interestingly, India’s consumption of pesticides per hectare is low (0.288 kg/ha) when compared with world averages—0.5 kg/ha against Korea’s 6.60 kg/ha and Japan’s 12.0 kg/ha. According to the pesticides industry statistics, India spends US $3/ha on pesticides compared with US $24/ha spent by Philippines, US $255/ha spent by South Korea and US $633/ha by Japan. Yet, despite a comparatively low use of pesticides in India, the contamination of food products in the country is alarming. About 20 per cent of Indian food products contain pesticide residues above tolerance level compared to only 2 per cent globally. No detectable residues are found in only 49 per cent Indian food products compared to 80 per cent globally. A pesticide is any substance or mixture of substances intended for preventing, destroying, repelling or mitigating any pest. Though often misunderstood to refer only to insecticides, the term pesticide also applies to herbicides, fungicides and various other substances used to control pests.

Pesticides and their metabolites have received particular attention in the last few years in environmental trace organic analysis because they are regularly detected in food products, surface/ground waters and soil strata throughout the world as consequence of their widespread use for agricultural and nonagricultural purposes. So it is the need of the hour to study the levels of pesticides residues in plants, water and soil and their fate in environment after its degradation.

It would be necessary to work out tolerance limits of pesticides residues in/on crops, soil and water and the efforts, therefore, are directed towards various residue analytical methods like TLC, GLC and HPLC etc. which are suitable for the purpose.

Soil testing kit is developed to determine the available nutrient status of soil by rapid test methods. With this system of soil testing, a farmer can test his own soil as often and, in as many places as he feels necessary, and after gauging the need of his soil, he can apply the fertilizers as required. The present mode of soil testing in laboratories usually takes few days and sometime weeks and the farmers may have to travel long distances to submit the soil sample.

To set up a soil-testing laboratory the minimum requirements are as follows:

8.1 Laboratory floor area

Minimum four rooms are needed. They are as follows:

1. Office room, floor size: 18’x 12’

This room is used for registration of the soil samples received, recording recommendations along with soil test results in laboratory book and in report sheet, their dispatch, accounts etc.

The analytical work in a soil-testing laboratory mainly involves standard chemical methods, suitably modified to permit handling of a large number of soil samples with the required degree of accuracy and speed. Many of the analytical operations are carried out more conveniently with help of common as well as sophisticated instruments.

The various instrumental measurements followed in soil and water-testing work in the laboratory can be broadly divided into two groups:

1) Determination of pH and electrical conductivity

2) Colorimetric, spectrophotometric

Abstract

Based on oxygen requirement, microorganisms have been classified into different groups, like facultative anaerobes, micro-aerophilic, aerotolerant and strict/obligate anaerobes. Obligate or strict anaerobes are the key components of anoxic environments and provide valuable ecosystem services like methanogenesis, sulphate reduction, metal reduction, degradation of pollutants etc. Apart from being valuable for the ecosystem, they are causative agents of human infections. They are the key players of human-gut microbiology, and can be used in bio-toilets, solid waste management, anaerobic digestion of waste, wastewater treatment processes and generation of waste to energy etc. Only few anaerobic microorganisms are pathogenic in nature. A mechanistic understanding about physiology and metabolism of anaerobic microorganisms is imperative for their industrial applications. Cultivation of these organisms is the first and very important step for the basic and applied study of anaerobes. Unlike cultivation of aerobic microorganisms anaerobic cultivation needs special care and facilities for successful handling of anaerobes. In the current chapter, We tried to incorporate the components and technicalities of anaerobic pre-reduced media preparation, cultivation and successful isolation of strict anaerobes. In addition, we also tried to discuss the different tools used for cultivation of anaerobes.

Abstract

Microbes are key ingredients of various ecosystems and backbone of modern biotechnology and industry. In addition to their cultivation, purification and characterization, preservation of microorganisms is equally important. Different preservation methods and protocols have been developed for long term preservation of microbes. Microbial Resource Centers (MRCs) are providing active services in the field of life sciences. National Centre for Microbial Resource (NCMR) at National center for Cell Science (NCCS), Pune is one of the MRCs. Unlike aerobes little work has been done in the area of cultivation and preservation of anaerobic microbes. In the previous chapter we have discussed the technicalities and problems of anaerobic cultivation. The aim of current chapter is to provide the recent overview of preservation of anaerobic microorganisms like methanogens, sulfate and metal reducers and the obligate anaerobes of clinical and industrial importance with fermentative mode of life style.

Abstract

Anoxygenic phototrophic bacteria (APB) are having the genetic potential of converting radiant energy into chemical energy useful for growth and metabolic activities without evolving oxygen. They are physiologically, metabolically and phylogenetically versatile group of organism spread in five distinct phyla; Proteobacteria (purple bacteria), Chlorobi (green-sulfur bacteria), Chloroflexi (green non-sulfur bacteria), Fir micutes (heliobacteria) and Acidobacteria. Different group of APB harbors distinct photosynthetic pigments, carotenoids, and a photosynthetic reaction center. These group of bacteria succeeds in a natural environment with light availability and presence of anoxic conditions as the pigment, and the molecular oxygen inhibits bacteriochlorophyll synthesis whereas few APB can grow in hypooxic as well as in aerobic conditions. Calvin-Benson-Bassham (CBB) pathway, reverse tricarboxylic acid (rTCA) cycle, and hydroxypropionate cycle are reported pathways for carbon assimilation in APB to fix carbon dioxide. Photosynthesis occurs in either intracytoplasmic membrane (ICM) or membrane bound chlorosomes and in the cytoplasm for few APB. APB have a wide range of potential applications including removal of H₂S from wastewater and gas streams, hydrogen production, degradation of xenobiotic, toxic metals and radioisotopes, work as host for the production of challenging membrane proteins, source of carotenoids and terpenoids, single cell protein, extensive applications in agriculture and production of bioactive compounds with antimicrobial, antioxidant and anticancer activity. The chapter is focused on the diversity of different types of APB, habitats, their growth requirements, photosynthetic machinery and biotechnological applications of APB.

Abstract

The anaerobic fungi are one of the early organisms in evolution which are commonly found in the digestive tract of ruminating and non-ruminating animals, (including herbivores) deep sea and earth, dumping sites, etc. In animals, these are considered the primary colonizers of the plant biomass ingested by them. Still their taxonomy was unclear for a long period of time. However, with the help molecular techniques, they are now classified under a separate phylum Neocallimastigomycota. There are 38 species known so far belonging to 11 genera. These have been identified based on both morphological data (like thallus, rhizoids, flagella per zoospore, etc.) and phylogenetic analysis. There is a need to explore the undiscovered anaerobic fungi and look for their potential in industrial applications and solutions to the present environmental problems. It can be achieved by improving techniques of sampling, isolation, maintenance and long term preservation. Animals like herbivores do not have the ability to produce enzymes for degrading the plant biomass and anaerobic fungi help them by producing a range of extracellular enzymes. This ability of anaerobic fungi are of use to humans in bioenergy (biogas production) and biomass degradation (by producing cellulases). Recent advances in metagenomics coupled with new methods of cultivation are helping immensely to know the uncultivated anaerobic fungal populations from the animal gut. The present book chapter discusses the past and present of anaerobic fungi, lacunaes and need for more work on this group of fungi, It focuses on the progress in sampling, isolation and preservation techniques, simultaneously discussing the advances in the application these fungi in biotechnology.