Chapter 6 - Molecular aspects of prokaryotic and eukaryotic cellulases and their modulation for potential application in biofuel production

Abstract

The plant cell wall is constituted by lignocelluloses in which cellulose is a predominant carbohydrate polymer that provides mechanical strength and rigidity to the plants. However, when plant biomass is exploited for biofuel production, the rigid crystalline nature of cellulose impedes the enzyme accessibility for its eventual breakdown to reducing sugar. Therefore, there is a requirement of robust cellulase to reduce the crystallinity of cellulose for its efficient biofuel usage. A wide range of microorganisms includes bacteria and fungi that produce cellulase that degrades cellulose by hydrolyzing the β-1,4-glycosidic linkages present in cellulose. In spite of the wide source of cellulase, there exists a bottleneck in both upstream and downstream processing of commercial cellulase production using wild strains. Thus, there is a dire need of a fast-growing, thermostable, and robust cellulase producer that has to be engineered through genetic modifications such as mutagenic and metabolic engineering approaches. This chapter envisages on the various genetic manipulations aimed at a better and cost friendly production of cellulase enzyme.