Hydrolysis of filter-paper cellulose to glucose by two recombinant endogenous glycosyl hydrolases of Coptotermes formosanus

• Published in: Insect science Vol. 17; no. 3; pp. 245 - 252
• Main Authors: Zhang, Dunhua, Lax, Alan R, Bland, John M, Yu, Jiujiang, Fedorova, Natalie, Nierman, William C
• Format: Journal Article
• Language: English
• Published: Melbourne, Australia Blackwell Publishing Asia 01-06-2010
• Subjects: 4 glucanase; amino acid sequences; b-Glucosidase; biofuel; Biofuels; Biomass; cellobiose; Cellulolytic enzymes; Cellulose; cellulose digestion; complementary DNA; Coptotermes formosanus; DNA libraries; endo-1,4-beta-glucanase; endo-β-1; endo‐β‐1,4 glucanase; Energy; enzymatic hydrolysis; enzyme substrates; Escherichia; Ethanol; expressed sequence tags; Glucose; glycosidases; Glycosyl hydrolase; Growth hormone; Hydrolysis; Isoptera; molecular cloning; molecular sequence data; nucleotide sequences; recombinant fusion proteins; subterranean termites; termite; β-glucosidase; β-葡萄糖苷酶; 内源性; 台湾乳白蚁; 基因重组; 水解酶; 纤维素材料; 过滤纸
• ISSN: 1672-9609; 1744-7917
• DOI: 10.1111/j.1744-7917.2010.01321.x

Genes encoding for glycosyl hydrolases （GH） in multiple families were recovered from an expression sequence tag library of Coptotermesformosanus, 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 ofbiomass 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.