Factors affecting hydrolytic action of xylanase during pennisetum saccharification: Role of cellulose and its derivatives

Abstract The effects of cellobiose and glucose as product inhibitors on the hydrolysis of lignocelluloses by cellulase has been confirmed, but the effect of these species on xylanase is still unknown. In this work, the inhibitory effects of cellulose and its derivatives on xylanase in the hydrolysis of Chinese pennisetum, a potential lignocellulosic biomass for the production of biofuels, was investigated. It was found that cellulose, cellobiose, and glucose all have negative effects on the hydrolytic action of endo-xylanase but not on that of β-xylosidase. Among these inhibitors, cellobiose exhibited the strongest inhibitory effect on xylanase, followed by glucose and cellulose. Cellulose (50 mg/mL), cellobiose (50 mg/mL), and glucose (50 mg/mL) decreased the hydrolysis yields of xylan by 10.4%, 19.7%, and 17.7%, respectively. Kinetic analysis revealed that both cellobiose and glucose competitively inhibited the activity of xylanase. The conclusions of this work help us further understand the inhibitory effects of cellulose derivatives on the hydrolysis of lignocelluloses.