Kinetic modeling of the enzymatic hydrolysis of pretreated cellulose



The production of sugars by the enzymatic hydrolysis of cellulose is a two-step process that includes conversion of the intermediate cellobiose to glucose by β-glucosidase. The hydrolysis was followed by analyzing the two sugar products (cellobiose and glucose). The enzyme showed maximum activity at pH 4.8. Thermal deactivation was significant at temperatures above 45°C. At 50°C (optimum temperature) thermal deactivation was found to follow first-order kinetics. Several models were tested by modeling the kinetics of the reaction. Their parameter values were determined by numerical optimization, including temperature dependence. The best fitting model was a competitive product inhibition for the two reactions in the operational range.