Plant cell wall degrading enzymes in biomass bioprocessing to biorefineries: A review

Plant cell walls are highly variable in terms of structure and composition across different plant groups, but almost all contain cellulose microfibrils embedded in a matrix of pectin, hemicellulose, lignin, and structural proteins with varying proportions of these compounds. Several microorganisms like bacteria and fungi like ascomycetes and basidiomycetes are the predominant degraders of lignocellulosic material in nature. A number of enzymes such as cellulases, hemicellulases, and pectinases produced by different life forms are known to target the cell wall of plants leading to its degradation. The ability of microorganisms to enzymatically degrade plant cell walls has been a hot topic of research interest from industrial units as the need for renewable fuels has been realized. There has been an increased focus on production of bioethanol from lignocellulosics and especially the possibility to use cellulases and hemicellulases to perform enzymatic hydrolysis of the lignocellulosic material. This chapter discusses some databases that can be regarded as of having high importance with respect to their utilization in bioenergy research.