Fermentation technology is the oldest of all biotechnological processes. Microbiologists consider fermentation as any process for the production of a product by means of mass culture of microorganisms. Biochemists consider fermentation as an energy generating process in which organic compounds act both as electron donors and acceptors; hence fermentation is an anaerobic process where energy is produced without the participation of oxygen or other inorganic electron acceptors (Rao, 2005). The production of enzymes, antibiotics, beverages, alkaloids and many more biological products are produced using fermentation technology. The bioprocess can be done with animal cells, plant cells and microbial cells to produce required products. The microbial cells are widely used because of its fast growth and short production period when compared with plant and animal cells. Using microbial cells two types of compounds can be obtained, intra cellular and extra cellular products. Extra-cellular products which are released by the microbes for changing the unfavorable conditions into favorable condition and survive and to safe guard themselves from other competitors. Cellulose is the primary product of photosynthesis in terrestrial environments and the most abundant renewable bio-resource produced in the biosphere (approx.100 billion dry tons/ year). Cellulose is found in plants as micro fibrils (2-20 nm diameter and 100 - 40 000 nm long). These form the structurally strong framework in the cell walls. Cellulose is mostly prepared from wood pulp. 11 Structure of Cellulose Cellulose is a linear condensation polymer consisting of Danhydroglucopyranose joined together by - 1, 4 glycosidic bonds with a degree of polymerization from 100 to 20,000. Anhydrocellobiose is the repeating unit of cellulose. Coupling of adjacent cellulose chains and sheets of cellulose by hydrogen bonds and Van der Waals forces results in a parallel alignment and a crystalline structure with straight, stable supra molecular fibers of great tensile strength and low accessibility. The cellulose molecule is very stable, with a half life of 5 8 million years for - glucosidic bond cleavage at 25C, while the much faster enzyme driven cellulose biodegradation process is vital to return to the carbon in sediments to the atmosphere. Cellulose biodegradation by cellulases and cellulosomes, produced by numerous microorganisms, represents a major carbon flow from fixed carbon sinks to atmospheric CO2 is very important in several agricultural and waste treatment processes and could be widely used to produce sustainable biobased products and bioenergy to replace depleting fossil fuels. The widely accepted mechanism for enzymatic cellulose hydrolysis involves synergistic actions by endoglucanase (EC 3.2.1.4), exoglucanase or cellobiohydrolase (EC 3.2.1.91) and - glucosidase (EC 3.2.1.21). Endoglucanases hydrolyse accessible intramolecular - 1, 4 glucosidic bonds of cellulose chains randomly to produce new 12 chain ends; exoglucanases cleave cellulose chains at the ends to release soluble cellobiose or glucose; and glucosidases hydrolyze cellobiose to glucose in order to eliminate cellobiose inhibition. These three hydrolysis processes occur simultaneously to degrade cellulose. The cellulose is madeup of two regions: i) Crystalline regions and ii) Amorphous regions. The crystalline regions are stable regions and the amorphours regions are unstable regions. The Endo glucanase acts first in the cellulose in the amorphous regions and break them and then the Exo glucanase or cellbiohydrolase acts in the broken outer regions. The combined action of Endo and Exo 13 glucanase forms glucose and cellobiose. The cellobiose is converted into glucose by the action of glucosidase. Thus the final product formed by the action of cellulase enzyme is glucose from cellulose. CELLULASE FROM FUNGI The fungi are a group of thallophytes characterized by the total absence of chlorophyll. The fungi

are usually multicellular and eukaryotic organism and considered as microorganism. They are found in every available habitat, majority of them are terrestrial, occurring in soil rich in dead and decaying organic matter. They can be differentiated as parasites that thrive on living organisms and saprophytes or saprobic fungi live on dead and decaying organic matter. Isolation of fungi from soil was received with much skepticism when Oedumans and Koning described in 1901. The capable of growing and producing mycelium in soil was a matter of controversy till mycologist S.A. Waksmann convinced other soil microbiologists, the important part played by fungi in the economy of soil. Previous to his work, soil microbiologists believed that fungi were present in the soil merely as spores drifted in from the air or as colonizers of the surface debris. We now know that by virtue of their intrusive habit fungi are the first and fastest colonizers of dead or dyeing plant residues within the soil and that it is bacteria that fill the role of secondary invaders, coming second in time if not in importance. Saprobic fungi are the main decomposers of dead plant materials. Yeasts are not generally able to decompose plant cell walls with polymeric components and thus saprobic fungi are mainly filamentous. Due to the great abundance of plant polysaccharides, fungi contribute significantly to the carbon turnover in nature. Much work has been done cellulases with 14 Trichoderma spp., specially T. viridae and T. reesei the later named after E.T. Reese, who with Mary Mandels have become synonymous with cellulose research.