|Cellulases are a group of enzymes catalyzing an enzymatic reaction system in which cellulose is decomposed into glucose, cellobiose or cellooligosaccharides. Cellulose is a long-chain polymer polysaccharide carbohydrate, of beta-glucose. It forms the
primary structural component of plants and is not digestible by humans. Cellulose is the principal constituent of the cell wall of plants. Mammals normally do not have this enzyme but ruminants often carry bacteria which have cellulase and can allow them to utilize cellulose as a carbohydrate source. Cellulase is produced by the fermentation of a nonpathogenic, nontoxicogenic strain of fungi Trichoderma viride, which is capable of decomposing cellulosic polysaccharides into smaller fragments, primarily glucose. Cellulase is also derived from Aspergillus niger.
Cellulase is an enzyme complex which breaks down cellulose to beta-glucose. Three types of enzymes make up the cellulase enzyme complex. Endocellulase breaks internal bonds to disrupt the crystalline structure of cellulose. Exocellulase cleaves two-glucose units from the ends of the smaller chains produced by endocellulase, resulting in the disaccharide cellobiose. Cellobiase or beta-glucosidase cleaves the beta linkage between the two glucose molecules in cellobiose. Cellulase derived from Trichoderma longbrachiatum is comprised of an enzyme complex consisting of cellulase, a glucosidase, cellobiohydrolase and a glucanase. This complex converts cellulose to beta-dextrins and ultimately to D-glucose. Cellulase is used as a digestive aid, particularly in animals, and for the management of flatulence.
Cellulases are key industrial enzymes used to breakdown biomass to fermentable sugars. Cellulose has been on the market as an industrial enzyme preparation and used as a main component of various products, such as detergents, fiber treating agents, additives for feed, and digestants. Cellulases can be used as a supplement in animal feed to decrease the production of fecal waste by increasing the digestibility of the feed. Cellulases can also be used to increase the efficiency of alcoholic fermentations (e.g., in beer brewing) by converting undigestible biomass into fermentable sugars. Cellulase is also used for commercial food processing in coffee. It performs hydrolysis of cellulose during drying of beans.