Combining Michaelis-Menten theory and enzyme deactivation reactions for the kinetic study of enzymatic hydrolysis by different pretreated sugarcane bagasse

Abstract

Conversion of lignocellulose to sugar depends on expensive cellulase and xylanase, hence, improvement of enzyme utilization is important. Enzymatic kinetics can guide researchers toward efficient enzymes utilization. Based on Michaelis-Menten theory and enzyme deactivation reactions, the novel kinetic models describing sugar (glucose and xylose) yield are deduced. The model based on second-order reaction is significantly superior compared to first-order reaction, which is verified by initial and maximum hydrolytic rate. Hydrolytic rate displays a linear relationship with enzyme loading. Sugar yield differs in enzymatic hydrolysis of various pretreated substrates, which is explained by the preferred model. Enzyme deactivation based on the model shows that higher enzyme loading results in reduced activity retention percentage, due to feedback inhibition of products and ineffective adsorption of substrate to enzyme during the hydrolytic process. Therefore, the developed model allows more in-depth study of enzymatic kinetics and provides a useful guide for efficient enzyme utilization.