Fungal Glycoside Hydrolases for Saccharification of Lignocellulose: Outlook for New Discoveries Fueled by Genomics and Functional Studies

Genome sequencing of a variety of fungi is a major initiative currently supported by the Department of Energy's Joint Genome Institute. Encoded within the genomes of many fungi are upwards of 200+ enzymes called glycoside hydrolases (GHs). GHs are known for their ability to hydrolyze the polysaccharide components of lignocellulosic biomass. Production of ethanol and "next generation" biofuels from lignocellulosic biomass represents a sustainable route to biofuels production. However, this process has to become more economical before large scale operations are put into place. Identifying and characterizing GHs with improved properties for biomass degradation is a key factor for the development of cost effective processes to convert biomass to fuels and chemicals. With the recent explosion in the number of GH encoding genes discovered by fungal genome sequencing projects, it has become apparent that improvements in GH gene annotation processes have to be developed. This will enable more informed and efficient decision making with regard to selection and utilization of these important enzymes in bioprocess that produce fuels and chemicals from lignocellulosic feedstocks.