Affiliation: | 1. Formosan Subterranean Termite Research Unit, Southern Regional Research Center, ARS, USDA, New Orleans;2. Food & Feed Safety Research Unit, Southern Regional Research Center, ARS, USDA, New Orleans;3. Department of Biochemistry and Molecular Biology, The George Washington University School of Medicine, Washington, DC The J. Craig Venter Institute, Rockville, MD, USA;4. The J. Craig Venter Institute, Rockville, MD, USA |
Abstract: | Abstract Genes encoding for glycosyl hydrolases (GH) in multiple families were recovered from an expression sequence tag library of Coptotermes formosanus, a xylophagous lower termite species. Functional analyses of these genes not only shed light on the mechanisms the insect employs to successfully use cellulosic materials as energy sources, which may serve as strategic targets for designing molecular-based bio-pesticides, but also enrich discoveries of new cellulolytic enzymes for conversion of biomass into biofuel. Our study demonstrated that cellulose could be converted to glucose by two recombinant endogenous glycosyl hydrolases (endo-β-1,4 glucanase in GH9 and β-glucosidase in GH1). While the former cleaved cellulose to cellobiose and cellotriose, the resulting simple cellodextrins were digested to glucose. Both of the Escherichia coli-expressed recombinant proteins showed properties that could be incorporated in a glucose-based ethanol production program. |