ENZYMATIC HYDROLYSIS OF CELLULOSE FROM STEAM-PRETREATED LESPEDEZA STALK (LESPEDEZA CRYTOBOTRYA) WITH FOUR TRICHODERMA CELLULASES

The hydrolytic potential of cellulases produced by Trichoderma viride, Trichoderma pseudokoningii, Trichoderma koningii, and Trichoderma reesei with addition of exogenous beta-glucosidase was evaluated on cellulose of steam-pretreated Lespedeza. The T. viride enzyme achieved the highest glucose conversion (90.09%), while T. pseudokoningii cellulase achieved the highest ratio of cellobiose to glucose (4.94%) at the end of hydrolysis. Enzymatic adsorption on the substrate was evaluated on filter paper activity and beta-glucosidase activity in the corresponding digest with the obtained T. cellulases. T. viride cellulase possessed an efficient adsorption-desorption on the substrate and reached the highest FPA difference (0.72 U/mL) among enzyme activities, indicating to its excellent hydrolysis capability. However, beta-glucosidase in T. viride cellulase system showed close bonding on the substrate, suggesting that efficiencies of adsorption-desorption on the cellulose are different between the entire cellulase system and beta-glucosidase. T. viride cellulase, with active endogenous beta-glucosidase (1.60 U/mL), has compatible synergism with the additional exogenous beta-glucosidase.