The structural and biochemical basis for cellulose biodegradation

The increasing petroleum price and the foreseeable depletion of fossil fuels has prompted research on bioenergy, particularly bioethanol and biobutanol from renewable lignocellulosic biomass, the primary component of which is cellulose. One key requirement of lignocellulose degradation is to improve the efficiency of a group of enzymes with general name cellulase, the collaboration of which degrades cellulose to glucose. Significant progress has been made in the last decade on understanding the structural and chemical properties of the substrate cellulose, the structural and biochemical properties of cellulases, their enzymatic mechanisms and the mechanism of synergistic catalysis by cellulases. This manuscript reviews the progress in the aforementioned fields, particularly the structural basis and enzymatic mechanisms of reactions leading to the degradation of cellulose. Based on these discoveries, popular models of enzymatic cellulose degradation are discussed, in the hope of benefiting further in-depth investigations of this complex, multi-component enzymatic reaction.© 2012 Society of Chemical Industry