long before he existed, the land was in fact regularly plowed and still continues to be thus

Earthworms-The intestines of the soil Aristotle. The plow is one of the most ancient and most valuable of man's inventions; but long before he existed, the land was in fact regularly plowed and still
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Earthworms-The intestines of the soil Aristotle. The plow is one of the most ancient and most valuable of man's inventions; but long before he existed, the land was in fact regularly plowed and still continues to be thus plowed by earthworms. It may be doubted whether there are many other animals which have played so important a part in the history of the world, as have these lowly organized creatures. Without the work of this humble creature, who knows, nothing of the benefits he confers upon mankind, agriculture, as we know it, would be very difficult, if not wholly impossible Charles Darwin. These are the words, which reveal the importance of Earthworms. It is well known that the earthworms have the ability to support the growth of plants and they can increase the fertility of the soil. There are about 3920 named species of earthworm so far reported worldwide. In India, so far, 509 species, referable to 67 genera and 10 families, have been reported (Kale, 1991). Earthworms play an important role in agro-ecosystem like enhancing decomposition, humus formation, nutrient cycling and soil structural development (Kladiviko et al., 1986). The practice of vermiculture is at least a century old but it is now being revived worldwide with diverse ecological objectives such as waste management, soil detoxification and regeneration and sustainable agriculture. Earthworms act in the soil as aerators, grinders, crushers, chemical degraders and biological stimulators. They secrete enzymes, proteases, lipases, amylases, cellulases and chitinases which bring about rapid biochemical conversion of the cellulosic and 1 the proteinaceous materials in the variety of organic wastes which originate from homes, gardens, dairies and farms. Recent works have elucidated some of the mechanisms by which earthworms enhance soil aggregation. Ingested aggregates are broken up in liquid slurry that mixes soil with organic material and binding agents. The defecated casts become stable after drying and also earthworms initiate the formation of stable soil aggregates in mining soils. Ecology of earthworms Earthworms are burrowing animals and form tunnels by literally eating their way through the soil. The distribution of earthworms in soil depends on factors like soil moisture, availability of organic matter and ph of the soil. They occur in diverse habitats specially those which are dark and moist. Organic materials like humus, cattle dung and kitchen wastes are highly attractive sites for some species. Earthworms are generally absent or rare in soil with a very coarse texture, in soil and high clay content, or soil with ph 4 (Gunathilagraj, 1996). Earthworms are very sensitive to touch, light and dryness. Water-logging in the soil can cause them to come to the surface. Worms can tolerate a temperature range between 5ºC to 29ºC. A temperature of 20ºC to 25ºC and moisture of percent is optimum for earthworm function (Hand, 1988). Biology of earthworms Earthworms are long, narrow, cylindrical, bilaterally symmetrical, segmented animals without bones. The body is dark brown, glistening and covered with delicate cuticle. They weigh about mg after 10 weeks. They have a muscular gizzard which finely grinds the food (fresh and decaying plant debris, living or dead larvae and small animals, and bacteria and 2 protozoa mixed with earth) to a size of 2 4 microns. The gut of the earthworm is inhabited by millions of decomposer micro-organisms. They are bisexual animals and cross-fertilization occurs as a rule. Copulation may last for about an hour, the worms then separate. Later the clitellum of each worm eject cocoon where sperms enter to fertilize the eggs. Up to 3 cocoons per worm per week are produced. From each cocoon about tiny worms emerge. Earthworms continue to grow throughout their life and the number of segments continuously proliferates from a growing zone just in front of the anus. Earthworms contain percent high quality lysine rich protein on a dry weight basis. They can be useful as animal feed. Usually the life span of an earthworm is about 3 to 7 years depending upon the type of species and the ecological situation. Eudrilus eugeniae Eudrilus eugeniae is an earthworm species indigenous in Africa but it has been bred extensively in USA, Canada, Europe and Asia for the fish bait market, where it is commonly called as the African Night-crawler. E. eugeniae is a large worm appearing brown and red to dark violet like animal flesh. Their length ranges from 3.2 to 14 cm, and 5 to 8 mm in diameter. It grows faster and better than other species. Life span of this worm ranges from 1 to 3 years. It grows rapidly and reasonably prolific. Under optimum conditions it would be ideal for animal feed protein production. However there has been relatively little work on the biology and ecology of this species. The African night crawler Eudrilus eugeniae is used extensively in commercial vermin culture especially in India. Increased attention is also being given to this species as a possible waste decomposer and as a protein source. 3 Coelomic fluid of earthworm A fluid within the coelom of earthworm is known as the coelomic fluid and this fluid is collected by stimulating them in different methods like mild electric shock, puncturing of coelomic cavity and worm water shock method. The coelomic fluid functions as a hydrostatic skeleton and also serves as the circulatory medium. The fluid contains cytolytic, agglutinating and/or antibacterial components, which are involved in the immune systems. Presumably the function of this system is to destroy membranes of foreign cell, a mechanism that causes cell death by cytosol release, and is attributed to the coelomycetes, which secrete humoral effectors into the coelomic fluid. Coelomic fluid is also reported for having anticancer activity. The high concentration of coelomic fluid exhibited toxic effect on HeLa cells, causing the cell lysis and break down into pieces. Antibacterial activity of coelomic fluid is reported to be selective. The coelomic fluid from earthworm is known to contain immunoactive cells and molecules involved in immune defense. Earthworm coelomic fluid is found to contain molecules that bind anti IgA and anti IgG. Elucidation of the earthworm binding site on anti IgG and anti IgA could make earthworm coelomic fluid a valuable reagent in immunological, chemical and biological research. Vermiculture biotechnology promises to usher in the Second green revolution by completely replacing the destructive agro-chemicals which did more harm than good to both the farmers and their farmland. Earthworms restore and improve soil fertility and significantly boost crop productivity. Earthworms excreta (vermicast) is a nutritive organic fertilizer rich in humus, NPK, micronutrients, beneficial soil microbes - nitrogen-fixing and phosphate solubilizing bacteria and actinomycetes and growth hormones auxins, gibberellins and 4 cytokinins. Both earthworms and its vermicast and body liquid (vermiwash) are scientifically proving as both growth promoters and protectors for crop plants. In the experiments with corn and wheat crops, tomato and egg-plants it displayed excellent growth performances in terms of height of plants, colour and texture of leaves, appearance of flowers and fruits, seed ears etc, as compared to chemical fertilizers and the conventional compost. There is also less incidences of pest and disease attack and reduced demand of water for irrigation in plants grown on vermicompost. Presence of live earthworms in soil also makes significant difference in flower and fruit formation in vegetable crops. Biomass of earthworms, a byproduct of Vermiculture Biotechnology (VBT) is rich in high quality protein and source of nutritive feed materials for fishery, poultry and dairy industries and also for human consumption (Rajiv et al., 2010). Vermiculture and environmental management Vermiculture is practiced for the mass production of earthworms with the multiple objectives of waste management, soil fertility and detoxification and vermicompost production for sustainable agriculture. The practice was started in the middle of 20th century and the first serious experiments were established in Holland in 1970, and subsequently in England, and Canada. Later vermiculture practices were followed in USA, Italy, Philippines, Thailand, China, Korea, Japan, Brazil, France, Australia and Israel (Edward, 1988). Collie (1978) and Hartenstein and Bisesi (1989) have reported on the management of sewage sludge and effluents from intensively housed livestock by vermiculture in USA. Vermiculture is being practiced and propagated on a large scale in Australia as a part of the Urban agriculture development program which utilizes the urban wastes. Australia s Worm grower association is the largest in world with more than 1200 members. 5 India has yet to appreciate the full importance of vermiculture despite the potential for the production of 400 million tonnes of vermicompost annually from waste degradation (Sinha, 1996). Senapati (1992) has stressed the importance of vermiculture for the management of all cellulosic wastes in India. Gunathilagraj and Ramesh (1996) and Gunathilagaraj and Ravignanam (1996) reported respectively about management of coir and sericultural wastes by earthworms in India. Kale et al. (1993), Seenappa and Kale (1993) and Seenappa et al. (1995) have each advocated vermicomposting and management on aspects of sugar factory waste, solid wastes from the aromatic oil industries, and distillery wastes in India. In 1998, the Government of India announced exemption from tax liability to all those institutions, organizations, and individuals in India practicing vermiculture on a commercial scale. Vermicomposting plants are operating in Pune and Bangalore with 100 tonnes day 1 capacity (Sinha, 1996). Chennai, Mumbai, Indore, Jaipur and several other Indian cities are also setting up vermiculture farms. Earthworms in general are highly resistant to many pesticides and have been reported to concentrate the pesticides and heavy metals in their tissues. They also inhibit the soil borne pathogens and work as a detoxifying agent for polluted soil (Davis, 1971; Ireland, 1983). These properties of earthworms can be utilized for effluent treatment and heavy metal and pesticides removal from industrial and agricultural wastes. Earthworms are important secondary decomposers and vermicomposting in nature is an ongoing process if the natural population of earthworms are undisturbed. Vermiculture engineers the growth of beneficial nitrogen fixing and decomposer bacteria and actinomycetes fungus in the degraded waste (vermicompost). India has voracious waste eater tropical species of earthworms. The warm and moist climatic conditions of India are also favorable for earthworm rapid biodegradation action. An earthworm promotes the 6 growth of beneficial decomposer bacteria in waste biomass and acts as an aerator, grinder, crusher, chemical degrader and a biological stimulator. Given the optimum conditions of temperature and moisture, earthworms eat the organic component of the waste biomass, which is finely ground into small particles in their gizzard and passed on to the intestine for enzymatic actions. The worms secrete enzymes; proteases, lipases, amylases, cellulases and chitinases in their gizzard and intestine which bring about rapid biochemical conversion of the cellulosic and the proteinaceous materials in the organic wastes (Hand, 1988). The gizzard and the intestine work as a bioreactor. Only 5 10 percent of the chemically digested and ingested material is absorbed into the body and the rest is excreted out in the form of fine mucus coated granular aggregates called vermicastings which are rich in nitrates, phosphates and potash. Earthworm participation enhances natural biodegradation and decomposition of wastes from 60 to 80 percent (given optimum temperature and moisture) thus significantly reducing the composting time by several weeks. The process of decomposition is odour-free because earthworms release coelomic fluids in the decaying waste biomass which have antibacterial properties and kill pathogens (Pierre et al., 1982). Earthworms also create aerobic conditions in the waste materials, inhibiting the action of anaerobic micro-organisms which release foul-smelling hydrogen sulfide and mercaptans. Eisenia fetida, E. andrei, Eudrilus eugeniae, Lumbricus rubellus and Perionyx excavatus are major waste eater and biodegrader earthworm species. They are used worldwide for waste degradation and are found to be very successful functionaries for the ecological management of organic municipal wastes (Edwards, 1988). E. eugeniae and P. excavatus are believed to be the more versatile waste managers (Graff, 1981; Kale et al., 1982). 7 Though earthworms are popular among the farmers to scientists for their plant growth promoting activities to anticancer activities, there are not enough studies available that has recorded the molecular basis of these findings. Hence, it was proposed to characterize the coelomic fluid and its various biological activities such as anti microbial and anti-cancer besides its obvious plant growth promoting property. Being a soil dweller and a known decomposer, a study has been conducted to evaluate the impact of textile effluent discharge the population of the earthworm. Eudrilus eugeniae species of earthworm was chosen for this study and the objectives were 1. Evaluation of different collection methods for coelomic fluid from Eudrilus eugeniae and its biochemical characterization. 2. Evaluation of the antimicrobial activity of the coelomic fluid on selected pathogenic strains. 3. To investigate the plant growth promoting property of the coelomic fluid in plant tissue culture system. 4. To evaluate the anticancer potential of coelomic fluid of Eudrilus eugeniae in SiHa cell line 5. To study the impact of textile effluent on the fecundity and population of Eudrilus eugeniae. 8 In 1881, Charles Darwin published his last book The formation of vegetable mould through the action of worms with observation on their habits shortly before his death. The book drew attention to the great importance of earthworms in the breakdown of dead plant material and the release of essential nutrients from it. However, only in last few decades, potential of earthworms for breaking down organic waste has been explored in depth and many large scale vermicomposting facilities have been developed all over the world with varying success. Earthworms The earthworm derives its name from the fact that it burrows and eats its way into the earth. Earthworms have been on the earth for over 20 million years. There are 3920 species of earthworms distributed throughout the world. Aquatic worms are called as microdrilli and terrestrial earthworms are known as megadrilli. In India, there are about 509 species of earthworms, belonging to 67 genera. Besides these, more than 20 species from other countries have been introduced into India. These are known as 'peregrines'. Earthworm occur in diverse habitats, organic materials like manures, litter, compost etc are highly attractive for earthworms but they are also found in very hydrophilic environment close to both fresh and brackish water, some species can survive under snow (Sharma et al., 2005). Classification of earthworm Kingdom: Animalia, Phylum: Annelida, Class: Oligochaeta, Order: Opisthopora, Family: Lumbricidae, Genus: A large number of genera have been described in literature, Species: A large number of species under each genus have been described in literature. Earthworms have also been classified on the basis of their ecological niche (Bouche, 1977) and feeding behaviour 9 (Lee, 1985) [Fig. 2.1]. A brief discussion of different ecological groups of the earthworms is given below: E. eugeniae P. excavatus Fig. 2.1: Classification of earthworms based on ecological groups and niche Epigeic species These species live above the mineral soil surface typically in the litter layers and plant debris and feed on them. These are phytophagous. Most of the species have insignificant role in humus formation and are not good for use in field conditions for soil reclamation. They have high reproductive rate and high cocoon production rate. However, their life span is relatively short. They show high metabolic activity and hence are particularly useful for vermicomposting. 10 Examples are Eisenia fetida, Eisenia andrei, Eudrilus eugeniae, Perionyx excavates and Drawida modesta. Endogeic species These species inhabit mineral soil beneath the top soil surface generally forming horizontal tunnels to the soil surface. They feed on soil more or less enriched with organic matter. They are probably important in improvement of soil texture and structure (pedogenesis) and are not much beneficial in organic matter decomposition and recycling of plant nutrients. Their reproduction rate is moderate and they have shorter life span. Example is Octochaetona thurstoni. Anecic species These are surface feeding earthworms that construct and live in permanent burrows in the mineral soil layers but come to the surface to feed on organic matter, mostly plant litter, and pull it into their burrows. They are important in burying surface litter. They are great help in incorporation of organic matter into the soil, and distribution and cycling of plant nutrients, and also in improvement of soil structure and texture (pedogenesis). These species have low cocoon production rate and limited reproductive capacity, but their life span is longer. Examples are Lampito mauritti, Lumbricus terrestris and Octochaetona serrata. A summary of characteristics used by Bouche to distinguish the earthworms on the basis of ecological niche is given in Table A (Gajalakshmi and Abbasi, 2004a). 11 Classification of earthworms based on feeding behavior According to their feeding habits, earthworms are classified into detritivorous and geophagus (Lee, 1985). Detritivores feed at or near the soil surface mainly on plant litter or dead roots and other plant debris in the organic matter rich surface soil or on mammalian dung. These include epigeic and anecic forms. These are also called as humus formers. Geophagus feed deeper beneath the surface, ingesting large quantities of organically rich soil. These include endogeic forms. These are also called as humus feeders. For the purpose of vermicomposting of different organic wastes, generally epigeic species of earthworms are used widely in India (Ismail, 2005). It is generally known that the epigeic species Eudrilus eugeniae, Perionyx excavates and Eisenia fetida have a potential as waste decomposers. In order to utilize these species successfully in vermicomposting and vermiculture all aspects of their biology and physical requirements must be known. The life-cycle of each of the three species are now well documented after intensive studies under controlled conditions. Venter and Reinecke (1988) presented studies on Eisenia fetida, Reinecke et al. (1992) on Eudrilus eugeniae, and Hallatt et al., (1990) on Perionyx excavatus. From a comparison of the lifecycle it is evident that all three species are prolific breeders, maintaining a high reproduction rate under favourable conditions of temperature, moisture and food availability. Food and feeding habits of earthworms Earthworms exhibit a high degree of niche diversity (Table A). Surface dwellers largely feed upon leaf litter on soil surface. Burrow formers swallow soil and derive nutrition from it. The quantity and quality of food available in an ecosystem determines population size, composition and diversity of earthworm community. In general, daily ingestion of feed varies 12 from 100 to 300 mg/g of worm body weight. According to one estimate, an earthworm can consume 8 to 20 g dung/year. So at a population density of 1,20,000 adults/ha, d
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