Fungal Enzymes for Bio-Products from Sustainable and Waste Biomass. Issue 7 (July 2016) - Gupta, Vijai K.
Abstract : Lignocellulose, the most abundant renewable carbon source on earth, is the logical candidate to replace fossil carbon as the major biofuel raw material. Nevertheless, the technologies needed to convert lignocellulose into soluble products that can then be utilized by the chemical or fuel industries face several challenges. Enzymatic hydrolysis is of major importance, and we review the progress made in fungal enzyme technology over the past few years with major emphasis on (i) the enzymes needed for the conversion of polysaccharides (cellulose and hemicellulose) into soluble products, (ii) the potential uses of lignin degradation products, and (iii) current progress and bottlenecks for the use of the soluble lignocellulose derivatives in emerging biorefineries. Trends: Fungi are excellent degraders of lignocellulosic biomass in nature. Fungal enzymes (including CAZy, AA) are essential to the conversion of polysaccharides into soluble products. Industrial conversion of lignin by microbial transformation generates products with numerous potential applications including serving as biofuels, with advantages over fossil fuels and processing of food crop-derived fuels. There are several remaining bottlenecks to the use of the soluble lignocellulose-derived components in emerging biorefineries. The biorefinery concept should be emphasized in many respects, focusing on the use of enzymes. The study of the interactome (enzymes plus lignocellulose complexity) will be key in the optimization process of biomass degradation. The breakdown of lignocellulose in the plant cell wall requires the recruitment of glycoside hydrolases with different mechanisms of action in a concerted action with ligninases. Genomic, transcriptomic, proteomic, and interactomic analyses are excellent tools for unraveling complex networks involved in enzyme-mediated hydrolysis of lignocellulose. Promising strategies for improving the economics of lignocellulose utilization by quantitative conversion of non-glucose-based polysaccharides sugars and lignins to valuable platform chemicals are emphasized.