Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
681738 | Bioresource Technology | 2011 | 6 Pages |
Enzymatic hydrolysis involves complex interaction between enzyme, substrate, and the reaction environment, and the complete mechanism is still unknown. Further, glucose release slows significantly as the reaction proceeds. A model based on Langmuir binding kinetics that incorporates inactivation of adsorbed cellulase was developed that predicts product formation within 10% of experimental results for two substrates. A key premise of the model, with experimental validation, suggests that Vmax decreases as a function of time due to loss of total available enzyme as adsorbed cellulases become inactivated. Rate constants for product formation and enzyme inactivation were comparable to values reported elsewhere. A value of k2/Km that is several orders of magnitude lower than the rate constant for the diffusion-controlled encounter of enzyme and substrate, along with similar parameter values between substrates, implies a common but undefined rate-limiting step associated with loss of enzyme activity likely exists in the pathway of cellulose hydrolysis.
► Development of kinetic model based on inactivation of adsorbed cellulase. ► Model predicts within 10% of experimental results for two substrates. ► Vmax decreases with time as adsorbed cellulases become inactivated. ► An undefined rate-limiting step likely exists during cellulose hydrolysis.