Synergism of fungal and bacterial cellulases and hemicellulases: a novel perspective for enhanced bio-ethanol production

The complex structure of lignocellulose requires the involvement of a suite of lignocellulolytic enzymes for bringing about an effective de-polymerization. Cellulases and hemicellulases from both fungi and bacteria have been studied extensively. This review illustrates the mechanism of action of different cellulolytic and hemi-cellulolytic enzymes and their distinctive roles during hydrolysis. It also examines how different approaches can be used to improve the synergistic interaction between fungal and bacterial glycosyl hydrolases with a focus on fungal cellulases and bacterial hemicellulases. The approach entails the role of cellulosomes and their improvement through incorporation of novel enzymes and evaluates the recent break-through in the construction of designer cellulosomes and their extension towards improving fungal and bacterial synergy. The proposed approach also advocates the incorporation and cell surface display of designer cellulosomes on non-cellulolytic solventogenic strains along with the innovative application of combined cross-linked enzyme aggregates (combi-CLEAs) as an economically feasible and versatile tool for improving the synergistic interaction through one-pot cascade reactions.