eChapters

INTRODUCTION

Fish is a dependable source of animal protein in developing countries like India. In recent years, with the rapid development of the aquaculture enterprises, the infectious diseases caused by fungus, bacteria, virus and parasites became more severe, resulting in huge economic losses. Due to certain unavoidable problems for diagnosing and treating diseases, losses are being born by the poor fish farmers of the country.

The issue is more relevant to rural area like north-east India, where soil and water are highly acidic due to the high content of ferrous ions and high rainfall and their management needs high inputs. The situation gets shoddier when the farmers do not get the access to water and soil laboratory to test their pond samples. It is very hard for the rural farmers to monitor their culture pond condition without any scientific tools and technical knowledge. Moreover, stresses due to over-crowding, wide temperature fluctuations, cold stress, global warming, microorganism, pesticides, insecticides, chemicals, contaminants etc.

INTRODUCTION

Northeast India comprises the contiguous seven sister states.viz., Arunachal Pradesh, Assam, Manipur, Meghalaya, Mizoram, Nagaland and Tripura and the Himalayan state of Sikkim. The Northeastern states of India are blessed with diversified fish fauna which assumes special interest due to the fact that the region is grained by two important drainages viz., Brahamaputra-Barak and Chindwin Irrawaddy. (Gurumayum and Choudhury, 2009). Riverine fisheries resources of Northeastern States comprise of 19,150 km of streams and rivers. Except the Brahmaputra and Barak Valleys in Assam and Imphal Valley in Manipur, the Northeast mainly comprises of Hills and Mountains which form 65% of its territory (Suguman, 1998).

INTRODUCTION

Assam is a heartland of indigenous groups. Since hundreds of years, many indigenous groups have been living in the state, maintaining their originalities in every sphere of life with difficulties. The tribal-indigenous groups constitute almost 12.4% of the total population of Assam. (Sentinelassam.com). Fishing is one of the major livelihood option of many indigenous fishers as the state is blessed with huge water resources with about 3.91 lakh hectare of water area in the form of rivers, beel, derelict water bodies and ponds and tanks. Besides swamps and low-lying areas, two major rivers and their tributaries have a high growth potential for fishing and could play a pivotal role in the socio-economic development and employment generation in the state. Indigenous fishers have developed a close and unique connection with the water resources and its environment in which they are depended for generation to generation for their livelihood. They have generated unique system of knowledge, innovation and skills relating to the uses and management of fishing activities. Over centuries, people have learnt how to get food and to survive in different environment. Farmers are very keen to observe the problems arising during fishing and seek solutions to adjust to their local environmental conditions. They continuously adapt and manage their fishing systems and in this way, they develop a rich storehouse of practical knowledge on their situation.

INTRODUCTION

The enemies of plants have been harming the organized agriculture ever since man started depending on plants for food. Fossil evidence indicates that plants were affected by disease since 250 million years ago. Conditions of food shortage and famines have been created by these enemies of plants. Naturally, the man had been obvious of their presence and proposed explanations and methods of combating them according to the knowledge available at that time all over the world. It is not true that attention to plant diseases was first given in the western countries. In the ancient Indian literature many plant diseases and their remedies were mentioned.

INTRODUCTION

The origin of fish culture in India probably dates back to 2000 years. Possibly, fishery activity started when the human settlement moved away from the riverbanks to the hinterland. As the days went by, the Indian fish farmers practice their own indigenous technology as a common practice through natural resource management (National Commission on Agriculture, Gov. of India, 1976). The close and intimate observation of farmers through their age-old practices has developed the expertise of acquiring knowledge in aquatic ecosystem in particular. Admittedly, the multifarious knowledge and skill possessed by local people can substantially contribute to productive efforts and endeavors (Dasgupta, 1993).

INTRODUCTION

Fishing is one of the oldest professions of humans. As the day went by, the fish farmers carry out their own indigenous technology as a common practice through natural resource management. In this line, different traditional fishing communities of West Bengal gained a vast experience in every sphere of aquaculture. Their innovation is based on their own knowledge derived from their day to day effort of solving problems. Actually this indigenous knowledge is the accumulated information, skill and technology of the local farmers derived from the close interaction with the nature. The intimate interaction of the farmers with aquatic ecosystems through their age old practices has developed huge expertise which is essential to be documented and disseminated. It will be helpful for aqua resource management as they can be shared in a, cost effective, eco-friendly as well as socio economically viable proposition.

INTRODUCTION

Over the past decades, as concerns about declines in local habitats, species, and livelihoods related to agriculture and allied sectors have increased, the potential contributions of local and traditional knowledge (LTK) to ecosystem research and management have been increasingly recognized (Thornton and Scheer, 2012). North Eastern region is well known as one of the 18 hotspot areas of the world and hence is blessed with rich biodiversity and fish fisheries resources. With more than 90% of population being fish eaters, there is heavy demand of fish but a wide gap exists between supply and demand. The region produces over 0.214 million tonnes of fish annually, with almost 50% coming from aquaculture.

INTRODUCTION

Ethno-entomophagy is the term used to describe the practice of consumption of insects as food by native human populations. Insects are an important source of protein for humans, either through direct consumption or as food supplements for livestock (DeFoliart, 1989). They are nutritious in terms of protein (40–75 g/100g dry weight) and minerals. Their protein is of high quality and has high digestibility (77–98%) with good concentration of essential amino acids (46–96% of the nutritional profile) (Verkerk et al., 2007). The biochemical composition and chemical analysis have revealed that they are comparable with other foods enriched with high proteins, fats, lipids, vitamins and mineral salts (Prasad, 2007). Insects generally have higher food conversion efficiency than other animals. They show a food conversion efficiency of about twice as efficient as pig and boiler chick and more than five times as efficient as beef cattle (Durst and Shono, 2010). Some of the important edible insects include grasshoppers, caterpillars, beetle grubs, adult winged termites, bees, wasps, winged ants, cicadas and a variety of aquatic insects.

INTRODUCTION

Jewellery has been a favorite form of adornment since time immemorial in all parts of the worlds and Indian is not an exception. The significance of jewellery in the country is evident from the fact that on many auspicious occasions, jewellery forms a part of gifts. Jewellery has not only been considered for the purpose of adoration, but it can also be sold to overcome the economic crisis. This way, jewellery also serves the purpose of insurance, which can be depended upon. To accentuate their feminine beauty, women use jewellery made of gold, silver and diamonds. Traditionally, jewellery has always been linked with wealth, power and status.

INTRODUCTION

The fermented products probably came into existence at least before the British Era in Northeastern states of India [before 1824, The Yandabu Agreement between British Govt. and Burma (now Myanmar)] when the British first introduced salt in the region. Interestingly, in all the fermented fish products of this region no salt is used as ingredient which is a major difference with the other fish based fermented fish products of Southeast Asian countries such as Nuac-mum of Vietnam, Budu of Malaysia, Patis of the Philippines etc. Even after the British Era, people used to treat salt as a highly valued and scarce commodity and they used to take an alternative commodity, for example khar in Assam, made from banana plant or papaya. Hence, they could not afford spending salt in fish preservation and they were bound to preserve fish in their own cheaper and easier way.

INTRODUCTION

Ethno-Veterinary Medicine (EVM) or Veterinary Anthropology refers to holistic and interdisciplinary study of traditional knowledge, skills, methods, practices and folk beliefs of the people about the health care of animal husbandry and production of livestock (McCorkle, 1986). It encompasses information on diseases and their control; remedies and clinical practices for treatment and prevention; management, feeding and breeding strategies; spiritual elements; and the use of human resources that hold the information and experience (Mathias, 2004).

INTRODUCTION

North East India is a rich storehouse of indigenous agricultural practices and local varieties of crops. The region comprising of the states of Arunachal Pradesh, Assam, Meghalaya, Manipur, Tripura, Mizoram, Nagaland and Sikkim can be physiographically categorized into the Eastern Himalayas, Northeast hills (Patkai-Naga Hills and Lushai Hills) and the Brahmaputra and Barak Valley plains. At the confluence of the Indo-Malayan, Indo-Chinese and Indian biogeographically realms, the NE region is unique in providing a profusion of habitats, which features diverse biota with a high level of endemism (Chatterjee et al., 2006). The northeastern region is rich in biological diversity and contains more than one-third of the country’s total biodiversity. This biodiversity and variability of the ecosystem are used and conserved by traditional communities through various informal institutions and using traditional ecological knowledge systems. Ethnic communities of the region practice their traditional cultivation practices of diverse crop suitable in different ecosystems solely on organic conditions without any external inputs to the system; and value the land and the environment for the sustainability of the system for future generations. There is no systematic record to describe what they are, what they do and how they do, how they can be changed, their operations, their boundaries and their applications.

INTRODUCTION

The North Eastern Hill (NEH) Region of India comprising the states of Arunachal Pradesh, Assam, Meghalaya, Mizoram, Manipur, Nagaland, Tripura and Sikkim lies between 20º5’ to 29º30' latitude and 89º49' E to 97º3' E longitude. The region possesses a great diversity in soil and climate as influenced by varied altitudes ranging from 18m MSL to more than 3000m MSL. In the entire region due to high rainfall (1800 mm to 3000 mm/year) humidity is very high (50-100%). The average minimum and maximum temperature is also comparatively low and ranges from below 0°C to a maximum of 35ºC. This region is very rich in natural resources with diverse flora and fauna.

Introduction

North East India, a mega-biodiversity centre and a hotspot (Myer et al., 2000) occupy 7.7% of India’s total geographical area supporting 50% of the flora (ca. 8000 species) (Rao, 1994), of which 31.58% (ca. 2526 species) are endemic (Nayar, 1996). It is a transitional zone between the Indo-China and Indo-Burma–Malaysian regions. This region is also a part of the vavilovian centre of biodiversity and origin of many important cultivated plant species and some domesticated animals (Agarwal, 1996). North Eastern Hilly (NEH) region of India supports a rich biodiversity spanning from tropical rainforests to alpine scrubs.  Takhtajan (1969) described the region as the “Cradle of Flowering Plants” because of its diversified angiosperms.  This rich biodiversity has a significant role to balance the ecosystem and has been used ethnologically by locals for various socio-economic and developmental purposes (Yumnam, 2008).

Introduction

Sustainable exploitation of fish stocks and conservation of fish habitat are matters of concern for fishery scientists and administrators all over the world. Worldwide there is a declining trend in natural fish catch (FAO, 2002) and India is no exception. Increasing harvest pressure, destructive fishing operations, introduction of exotics, are examples of factors from within the sector responsible for increasing pressure on fish stocks. The decline in open water catch has been a serious issue in fisheries as millions of rural households depend on fishing to maintain their livelihood incomes, and because fish is a major protein source in the globe. However, the government in several countries is addressing the issue in a number of ways, such as: (i) moving towards biological management from revenue-oriented management; (ii) involving resource users in capture fisheries management to maintain natural productivity; and (iii) starting programs such as rehabilitating of degraded habitats (FAO, 1999).

INTRODUCTION

Knowledge is a familiarity with someone or something, which can include facts, information, descriptions, or skills acquired through experience or education. It can refer to the theoretical or practical understanding of a subject. It can be implicit (as with practical skill or expertise) or explicit (as with the theoretical understanding of a subject); it can be more or less formal or systematic.While many would agree that one of the most universal and significant tools for the transfer of knowledge is writing (of many kinds), argument over the usefulness of the written word exists nonetheless, with some scholars skeptical of its impact on societies. People are often internalizing new information which they perceive to be knowledge but in reality fill their minds with false knowledge.

INTRODUCTION

Indigenous knowledge is the knowledge of the indigenous people inhabiting different geographical regions of the world with their own language, culture, tradition, belief, folklore, rites and rituals. In course of their close interactions with nature and natural resources, they are to make a certain decisions as to solve their problems they encounter in their day to day life while managing the land and environmental resources for survival.

Several researchers explained traditional knowledge as holistic, encompassing many fields of scientific knowledge, such as climate, hydrology, soils, plants and animals (Howes and Chambers, 1980, Jungerius, 1985, Wilken, 1987, Agrawal, 1995). Therefore, indigenous knowledge so developed is based on necessities, instinct, curiosity and observations of ethnic groups to mitigate the immediate problems. Several logical observation was used by them in the decision making process as to how, when and where to act depending on the situations.

Precautions to be taken while working in the laboratory for personal safety and to prevent any hazards.
    1.    Be vaccinated against dangerous viruses viz., rabies and hepatitis B as persons can contract infection while working with these organisms.
    2.    Use eye protection viz., goggles, spectacles etc to avoid splashing microbes into the eyes. 
    3.    Do not rub eyes with contaminated hands or objects.
    4.    Do not eat or drink anything in the microbiology laboratory as it will contaminate the laboratory.

Early and accurate diagnosis of disease is of prime importance for both the successful treatment of the patient and in limiting the spread of disease in the community. It is in this context that immunodiagnostic methods are now being used extensively since they can be extremely sensitive and highly specific. Among the most successful methods are those utilizing labelled antibodies or antigens. Examples of these are immunofluorescence in which antibodies labelled with fluorescent dyes are utilized and radioimmunoassay in which antigens or antibodies are labeled with isotopes. Both of these procedures have proved to be of great value for particular purposes.

Principle

The infectivity of a virus may be neutralized by specific antibody when they are mixed and incubated. In some cases, the addition of homologous or guinea pig complement to the mixture enhances neutralization, particularly when early antiserum is used. Serum must be inactivated by heating at 560C for 30 minutes to inactivate complement or to remove non-specific virus inhibitors. Serum-virus mixtures are inoculated into appropriate cell cultures, which are then incubated until the only virus controls develop cytopathic effects. Antibody by neutralizing the infectivity of the virus, protects the cells against virus destruction.

Processing

On arrival in the laboratory, the specimens are processed immediately or refrigerated until processed. For inoculation into animal/cell culture/embryonated eggs (EE), swabs are shaken in fluid medium, faeces are dispersed in fluid medium and tissue specimens are homogenized in a high speed blender/pestle and mortar with the help of an abrasive like powdered glass or sand. Good quality hard sand should be properly washed in distilled water, treated with HCl, washed thoroughly, dried and sterilized before use. Generally the infective tissue is homogenized in a few ml of buffer usually having a pH of 7.2 to 7.3 to make about 10% tissue suspension. The suspension is centrifuged at about 1000g for 10-15 minutes to sediment the tissue debris and coarse materials.

Bovine
 
1.    PPR    Eye, mouth, rectal swab in PBS on ice, 10 ml blood  in anti-coagulant at height of temperature, Prescapular lymph node, spleen, piece of intestine on ice, lung, liver, spleen, tonsil in 10% neutral formol saline solution.

The tentative diagnosis of viral diseases of livestock can be made by clinical symptoms alone. The clinical diagnosis is substantiated by the laboratory to obtain a precise, correct and prompt diagnosis. The success however depends on the collection of suitable materials in proper transport medium at a particular stage of disease condition and its dispatch to the laboratory in a manner that little or no alterations occurs in the specimen. This would facilitate the isolation and identification of the causative viral agents easily.

The most important property of a virus is its infectivity or ability to invade a cell and parasitize that cell to replicate itself. To measure infectivity, a titre is defined as the given number of infectious virus units/unit volume and an infectious unit is the smallest amount of virus that produces some recognizable effect in the host system. There are two basic types of infectivity assays (a) Quantal assays and (b) Quantitative assays.

Quantal assays do not measure the number of infectious virus particles present in the inoculum but denote a value for the virus titre where measurement is based on an all or none principle, CPE + or -, dead or alive etc. In the quantitative assays, the number of virus particles present in the suspension can be quantified.

Cell culture is the most convenient and widely used system for the isolation and propagation of many viruses. Either primary cell culture or established cell lines can be used to isolate the suspected viruses. One can normally get 10-100 virus particles per cell inoculated. Many details of the infection process are controllable to a high degree (including cell density, age, multiplicity of infection (M.O.I.), medium composition, cell type and length and temperature of incubation). Many cell types from different species can be susceptible to a particular virus and vice versa. For replication to occur, the cell type used must be permissive for a particular virus under study.

Enumeration of cells is essential to determine the multiplicity of infection, efficiency of plating and to obtain the specific number of cells for an experiment. The concentration of cells of a suspension can be counted using a haemocytometer. Each chamber is divided into a grid of nine large squares. Each large square is 1mmX1mm (area 1 mm²) and the depth is o.1 mm. The volume of each square is 0.1 mm³ or 10^-4 cm³. Since 1 cm³ is equal to 1 ml, the number of cells per ml of suspension can be obtained by multiply the average count per large square by 10⁴ and reciprocal of dilution factor. Dilution is made in such a way that one large square contain about 20-60 cells. The haemocytometer chambers should be filled by capillary action and cell clump are counted as one cell. A total count does not distinguish between living and dead cells. The number of viable cells can be determined by staining the cells with trypan blue or erythrosine B. In trypan blue staining cells appear as unstained whereas dead cells appear as blue.

Cell culture contamination continues to be a major problem and a subject of great concern. Contamination may enter the cell culture system as physical, chemical or biological component of the environment and biological contamination represent the greatest threat as living organism metabolize and replicate. Replication increases the titre of the contaminant.
 
Physical contamination : Physical components of cell culture systems such as radiation, irradiation (UV light and fluorescent light), temperature extremes can cause reduced cell growth and cell death. To minimize the problems, incubators should be located where ambient temperature is relatively constant and no vibration (near centrifuge). Media and media components should not be stored in glass door refrigerators, next to radioisotopes, bench tops or outside the refrigerator or in the hood for prolonged period.

Early passage cell lines are relatively unstable and go through a period of adaptation to culture. However, between 5^th and 35^th generation (human diploid fibroblasts), the culture is fairly consistent although it varies from one cell to another cell. Finite cell lines should be preserved after adaptation but before senescence (getting older). Cells should be preserved to protect cell line instability, availability in case of contamination, incubator failure or accidental loss.

There are a number of different cell lines derived from human and animals. With the dramatic increase in numbers of cell lines, the risk of intraspecies and interspecies cross contamination rises proportionally. It is particularly a major problem in laboratories where many different cell lines of human and animal origin are handled at a time. The purity of the primary cell or continuous cell lines and species of its origin should be checked on a regular basis to authenticate the cell line identity. In the absence of such monitoring, inter and intra species cell line contamination are likely to occur in the laboratory resulting in loss of investigator’s time effort and resources. The advantages of working with a well defined cell line free from contaminating organisms would appear obvious.

Small volume cultures are useful for experiments such as studying cell morphology, titration of viruses, plaque assay, pock assay, SNT and to compare the effect of agents on growth and metabolism. However, there are other application where there is a need of large number of cells such as extraction of DNA/RNA from cells, production of viruses for vaccine production and a number of products namely interferons, interleukins, hormones, enzymes, antibodies, glycoproteins etc. The large quantity of cells can be obtained by using a large number of flasks/bottles but it is tedius, labour intensive, expensive and there is a risk of contiamination. Although the unit processes are more cost effective and efficient, it needs some modification to overcome limiting factors such as oxygen depletion, shear damage and metabolic toxicity. There are a number of aberrations available to scale up cell culture described below.

If the concentration of cells in suspension cell culture has reached to 7X10⁵ cells/ml, it is to be subcultured. Suspension cells are diluted to concentration of approximately 1X10⁵ cells/ml although it varies from cell line to cell line. So, to subculture into a 3 litre glass flask using 500 ml of suspension of cells, there is a need of 5X10⁷ cells. As the concentration of cells is 7X10⁵ cells/ml, there is a need of 71.4 ml of cells. Adherent cells are put in the culture flasks at a concentration of 5X10⁴ cells in a 25 cm² flask. For example, after trypsinization, the cells have been resuspended in 5 ml of medium and cell concentration is 1X10⁵ cells/ml or total number is 5X10⁵ cells. If one wants to put cells into two 25 cm² flasks each containing 5X10⁴ cells in 5 ml volume, there is a need of 1X10⁵ cells, which can be obtained from one ml of cell suspension (1X10⁵ cells/ml).

Vero (monkey, African green, kidney) 
Morphology: Fibroblast
Species:, African green monkey 
Tissue: Kidney

Properties: Virology, virus titration, virus replication, plaque assays, bacterial cytotoxicity

In may cases, it becomes necessary to send the cells from one laboratory to another laboratory within or outside the country. The ideal method is to fill the flask containing cells at log/exponential phase with growth medium, tightly close the cap, seal it with parafilm and tape and pack it properly with polythene containing tissue paper and cotton. The tissue paper and cotton is used to soak the medium in case of accidental breakage. The polythene containing tissue culture flask having the adherent cell sheet should again be packed with thick paper. Finally, it is to be kept in a wooden/metal box or container.

Cell growth and cell passage : Different types of cells have different growth requirements but in all cases the surrounding medium must supply all the essential nutrients. The temperature, pH, osmolarity and humidity must be kept within limits. Again, toxic or inhibitory substances must not be allowed to accumulate. Serum, a source of macromolecular growth factors, is essential to the growth of many cell types. Anchorage dependent cells require nontoxic or biologically inert glass or plastic surface for attachment.

Primary cells are often preferred to established cell lines as they better represent the cells in vivo in terms of activity and functions. On the other hand, there is significant difference between original culture and present culture and even between cultures of the same cells in different laboratories. The rate of growth increases and there is change in chromosome numbers of lines over the time. The differences in phenotypes can cause problems in comparison and interpretation of results. The advantage of cell lines are ease handling, grow continuously, large yield and readily available. Primary cell cultures compared to established cell line are more fastidious in their growth requirements because many cell lines are derived from tumour tissue and demonstrate reduced growth factor requirements.

Cell culture medium : To grow cells in in vitro, environment should be as close as possible to in vivo condition. But a number of factors are important to grow cells in vitro namely substrate, temperature and medium. There is a number of ready made medium available commercially and made the cell culture work easier. Any successful medium consists of isotonic buffer solution containing inorganic salts, amino acids, vitamins, a energy source and various supplements. Usually serum or serum replacement is used as supplement.

Once cells are obtained from a culture collection or isolated from animal tissue,, cells are put in the flask with growth medium. The cells are inoculated at a density of 104-105 cells/ml to get a concentration of 106 cells/ml or 105 cells/cm2 in a solid surface in 2-3 days because of nutrient limitation, accumulation of toxic metabolite or lacking of growth surface.

A cell culture laboratory should allow the sterile handling of cultured cells with no or minimum level of contamination. The growth of bacteria and fungi is very high and no level of contamination can be allowed in animal cell culture. However, it is impractical to design a laboratory free from potentially contaminated microorganism. Further, it is possible to establish a laboratory with minimal risk of contamination. Several points should be taken into consideration while designing a new cell culture laboratory.

A finite growth capacity is a characteristic of all cells derived form the normal animal tissue. The cells pass through a series of age related changes before being incapable to divide further. The finite number of generations of growth is a characteristic of the cell type, age and species of origin and referred to as the “Hayflick limit”. The cells derived from embryonic tissue have a greater growth capacity than those derived from adult tissue.

Types of cells : Animal cells are usually defined by the tissue of their origin. On the basis of morphology, they can be divided into 5 types.

    1.    Epithelial cells : Epithelial tissues consist of a layer of cells which cover organs and line cavity. Example skin and the lining of alimentary canal. They grow well as single cell monolayer in culture.

    2.    Fibroblast cells : Connective tissue form the major structural component of animals. The tissue contains fibroblasts and most widely used cell in the laboratory. Fibroblasts are bound to the fibrous protein collagen in the connective tissue. They have excellent growth characteristics.

The best environment for growing cells is similar to  the conditions what they experience in vivo. A number of various environmental factors affecting the tissues are :
 
    (1)    Temperature : In living matter, complicated chemical reactions are happened at comparatively low temperature.  In most of the mammalian and avian tissues the temperature  is 37^ºC to 38.5^ºC. If the temperature is enhanced to 45^ºC, cells are destroyed within  an hour but survive 12-24 hours at 42^ºC. It is applicable to most of the fibroblasts and epithelial  types of cells arising  from  mammalian tissues. Some of the mammalian cells ( human skin epithelial cells)  and amphibian cells  prefer lower temperature but fish tissue will not survive beyond 20^ºC.

The cell is the unit of structure of all plants and animals. With increasing complexity of organization, masses of different cell types tend to become localized and to form recognizable patterns. An aggregation of cells forming a definite pattern is called tissue. A still higher level of organization, tissues aggregate to form organs. The animal cell is a highly organized structure. Plant cell is different from animal cell  by having a cellulose cell wall.  There are a number of well defined structures viz., nucleus, mitochondria, lysosomes, Golgi apparatus etc in the cell. Animal cells also have centrioles whereas plant cells contain plastids such as chloroplasts. The remainder of the cell is the cytoplasm.

Cell culture has become one of the major tools used in the life sciences today. Viruses replicate only within the living cells. With the advent of cell culture technique, it has become easier to grow the viruses under in vitro condition (cell culture). Viruses are usually propagated in cell culture, embryonated hen’s egg, laboratory animals or natural hosts. In 1949, Enders, Weller and Robbins first reported that polio virus could be grown in cultured non-neural cells with the production of recognizable cytopathic changes. Although the cell culture technique has been evolved long back, it is only since the advent of antibiotics that cell culture became a matter of simple routine technique. Aseptic precautions are still essential, but the problems of contamination with bacteria, mycoplasma, fungi and yeasts can be checked by antibiotics and anti-fungal agents. The term in vitro literally means ‘in glass’ although today most cell culture is performed in or on plastic.

Introduction

Bioremediation can be defined as elimination, attenuation or transformation of polluting or contaminating substances by the use of biological processes, to minimize the risk to human health and the environment. Bioremediation of contaminated soil and water uses microbes (e.g. bacteria and fungi) to convert pollutants to harmless or more environmentally acceptable products and minimizes the risk to human health in a natural or managed process.

Introduction

Soil forms the base of the lithosphere on earth and is a fundamental and irreplaceable versatile three dimensional dynamic system that supports majority of terrestrial plant and animal life on earth. This soil system contains mineral (sand, slit and clay forming basic soil structure) and organic matter as well as marginal air and water contents. The soil organic matter content of the soil system constitutes every fraction of matter in various stages of decomposition that once was associated with the body, body parts, exudates, tissues and cells of living organisms including plants, animals and microorganisms. It is the product of continuous cycling of the compounds synthesized by autotrophic plants among the three kingdoms viz microbes, plants and animals. The decomposition of the organic residues in soil is performed primarily by the resident soil microflora termed as microbial decomposers; though initially the larger and complex organic material is broken down, devoured upon, chewed, regurgitated and transformed into smaller bits by larger soil faunal forms (earthworms, beetles, springtails, and collembola, the macro (large) to mesofauna) on which soil microbial forms could act upon.

Introduction

Introduction of improved high yielding varieties of crop plants, use of modern agricultural practices coupled with essential control of pests of food and fiber crops have significantly contributed towards increasing the food production in green revolution era in India. Pesticide application forms the foremost limb in hiked agricultural food production and management practices. The production and post production management of crop yield requires increased use of pesticides.

Introduction

India being a developing nation is trying to reach a balance in ever increasing population with marginal increase in crop production. There occurred a bigbang in crop production during the green revolution era however this also resulted in creation of infertile, barren lands with low chemical nutrient input responsive soils. Soil fertility is the major constraint among resource poor Indian farmers as lesser benefits are harnessed by use of newer agricultural protocols/tools/products viz improved varieties, productive technology from less fertile soils. There is dire need for looking for the alternative technologies of food or crop production to satiate the hunger of burgeoning Indian population. Today there is enormous emphasis on the conservation facets of soil fertility and crop productivity which are the instrumental philosophies in sustainable agriculture. Biofertilizers are the cost effective, ecofriendly and renewable resource of plant nutrients that could well supplement the use of already functional and popular chemical fertilizers for obtaining increase in crop yield without over hazardous impacts on various facets of soil chemistry, fertility and microbial diversity to attain sustainable agricultural system.

Introduction

Vesicular arbuscular mycorrhizae are fungi that exhibit symbiosis with roots of higher plants. The term vesicular arbuscular is derived from characteristic structure i.e. ‘branched hyphae or arbuscles’ that are formed with in the root cortical cells and vesicles or ‘swollen lipid storing organs’ that occur with in or between them.

Introduction

Lithosphere, including the earth’s crust, is helpful in providing the base or medium for sustenance of most life processes and forms, interwoven in fine network interdependencies within themselves and the environment surrounding them i.e. ecosystems. Terrestrial ecosystem contains an important dynamic living matrix termed soil, which is critical for agricultural production and food security. Soil forms the medium for growth and maintenance of a variety of plant species while the plant roots in the soil represent a four dimensional region in space and time of profuse activity relative to the bulk soil, revolving around pH, nutrient, redox potential, and exudate gradients changing as distance from the root increases (Marschner, 1995). The soil region adhering the plant roots is being strongly influenced by the presence of these roots and is characterized by high rates of microbial population and activity and referred as rhizosphere (the soil adhering to plant roots).

Introduction

Increased population pressure, reduced length of fallow, deforestation and improper agricultural practices have led to widespread soil degradation in many parts of the developing world which has culminated in appearance of determinative manifestations of environmental damage in form of inadequate replenishment of soil nutrients and organic matter. Phosphorus is second major plant growth limiting nutrient and despite being in abundance in soil (organic and inorganic form), P deficiency is becoming critical in many soils throughout world as these soils have free available P concentration (generally) not higher than 10mM even at most soluble slight acidic pH (Arnou, 1953). Moreover, consistent P deficiency threatens to disturb the use efficiency of applying other nutrients. Hence to preserve the sustainability of agriculture it is foremost to rebuild soil fertility and maintain/improve the soil biodiversity to reap hiked current levels of productivity and farm income.