Chapter 12 - Interaction Between Solid Substrate and Cellulase Enzymes in Cellulose Hydrolysis

Abstract

Publisher Summary Cellulase enzymes are strongly adsorbed by cellulose. The adsorption characteristics of cellulase onto cellulose is intimately related to the structure and properties of both the enzymes and the solid substrate. This chapter reviews structure and properties of both the enzymes and the solid substrate. It discusses cellulose structure and properties and unit cell structure of cellulose. Cellulose is a high molecular weight linear polymer of cellobiose units connected by β-1, 4-glucosidic linkages. Each cellobiose unit consists of two anhydroglucose molecules. The unit cell structure of crystalline cellulose has been elucidated by X-ray diffraction studies. For any enzymatic reaction to occur, direct physical contact must be made between the enzyme and its substrate. This is also true for the enzymatic hydrolysis of cellulose. Therefore, the rate of reaction should be a function of the cellulose surface area accessible to the cellulase. Cellulase refers to a group of enzymes that catalyze the hydrolysis of the β-1, 4-linkages of the cellulose molecule. Complete enzymatic cellulose hydrolysis of native cellulose to glucose occurs as a result of the presence of different enzyme components. The chapter explains the structural properties of cellulases and fragmentation of cellulose fibers by cellulose. It focuses on the interaction between the solid substrate and cellulase enzymes in cellulose hydrolysis.