There are three major types of cellulase activities: β-1,4-endoglucanase (EC3.2.1.4), exoglucanase (including cellobiohydrolase (EC3.2.1.91) and cellodextrinase (EC3.2.1.74), and β-glucosidase (EC 3.2.1.21), based on their modes of catalytic action. Endoglucanases randomly cut internal sites on crystalline cellulose surfaces, generating new chain ends. Cellobiohydrolases act in a processive manner on the reducing or non-reducing ends of cellulose and liberate cellobiose as major products. β-Glucosidases hydrolyze soluble cellodextrins and cellobiose to glucose. Cellodextrinases hydrolyze soluble cellooligosaccharides, producing cellobiose but exhibit little or no activity against insoluble cellulose or carboxymethylcellulose (CMC). Cellulases act synergistically to hydrolyze cellulose into glucose (Lynd et al. 2002). Cellulases are classified into different glycoside hydrolase families (GH) (http://www.cazy.org/Glycoside-Hydrolases.html) based on amino acid sequence similarity (Henrissat 1991).