Abstract:
Recently, the global attention has been shifted toward improving second-generation biofuel, which seems to be the best alternative in solving the challenges of feedstock for bioethanol production as the demand for food is increasing daily due to growing human population. However, finding economically viable hydrolytic enzymes that can degrade lignocellulosic biomass with higher specific activity, better stability, lower susceptibility to inhibition, and improved physicochemical properties has been a bottleneck to researchers. These limitations therefore provide a possibility for strain improvement through genetic and metabolic engineering technologies. This chapter critically examines the classification of cellulolytic enzymes (cellulases and xylanases), methods for hydrolysis, strain improvement strategies through mutagenesis, genetic and metabolic engineering, and directed evolution, epigenetic, promoter, gene deletion approaches, and artificial chimera. Economic outlook and future prospect of cellulolytic enzymes were also examined.
