title: A highly active beta-glucanase from a new strain of rumen fungus Orpinomyces sp.Y102 exhibits cellobiohydrolase and cellotriohydrolase activities.
abstract: A new strain of rumen fungus was isolated from Bos taurus, identified and designated Orpinomyces sp.Y102. A clone, celC7, isolated from the cDNA library of Orpinomyces sp.Y102, was predicted to encode a protein containing a signal peptide (Residues 1-17), an N-terminal dockerin-containing domain, and a C-terminal cellobiohydrolase catalytic domain of glycoside hydrolase family 6. CelC7 was insoluble when expressed in Escherichia coli. Deletion of 17 or 105 residues from the N-terminus significantly improved its solubility. The resulting enzymes, CelC7(-17) and CelC7(-105), were highly active to β-glucan substrates and were stable between pH 5.0 and 11.0. CelC7(-105) worked as an exocellulase releasing cellobiose and cellotriose from acid-swollen Avicel and cellooligosaccharides, and displayed a Vmax of 6321.64μmole/min/mg and a Km of 2.18mg/ml to barley β-glucan. Further, the crude extract of CelC7(-105) facilitated ethanol fermentation from cellulose. Thus, CelC7(-105) is a good candidate for industrial applications such as biofuel production.
authors.affiliation: Department of Biological Science and Technology, National Pingtung University of Science and Technology, 1, Shuehfu Rd., Neipu, Pingtung 91201, Taiwan, ROC.
authors.forename: Yo-Chia
authors.initials: YC
authors.lastname: Chen
authors.affiliation: Department of Biological Science and Technology, National Pingtung University of Science and Technology, 1, Shuehfu Rd., Neipu, Pingtung 91201, Taiwan, ROC.
authors.forename: Wan-Ting
authors.initials: WT
authors.lastname: Chen
authors.affiliation: Graduate Institute of Bioresources, National Pingtung University of Science and Technology, 1, Shuehfu Rd., Neipu, Pingtung 91201, Taiwan, ROC.
authors.forename: Jeng-Chen
authors.initials: JC
authors.lastname: Liu
authors.affiliation: Institute of Organic and Polymeric Materials, National Taipei University of Technology, 1, Sec. 3, Chung-Hsiao E. Rd., Taipei 10608, Taiwan, ROC.
authors.forename: Li-Chu
authors.initials: LC
authors.lastname: Tsai
authors.affiliation: Department of Biological Science and Technology, National Pingtung University of Science and Technology, 1, Shuehfu Rd., Neipu, Pingtung 91201, Taiwan, ROC. Electronic address: hlcheng@mail.npust.edu.tw.
authors.forename: Hsueh-Ling
authors.initials: HL
authors.lastname: Cheng
mesh_terms: D000818:Animals; D001483:Base Sequence; D056804:Biofuels; D015153:Blotting, Western; D002417:Cattle / Q000382:microbiology*; D044602:Cellulases / Q000235:genetics / Q000378:metabolism*; D043366:Cellulose 1,4-beta-Cellobiosidase / Q000235:genetics / Q000378:metabolism*; D002855:Chromatography, Thin Layer; D016000:Cluster Analysis; D017931:DNA Primers / Q000235:genetics; D004926:Escherichia coli; D015723:Gene Library; D007218:Industrial Microbiology / Q000379:methods*; D008969:Molecular Sequence Data; D020085:Neocallimastigales / Q000166:cytology / Q000201:enzymology* / Q000235:genetics; D010802:Phylogeny; D012417:Rumen / Q000382:microbiology*; D017422:Sequence Analysis, DNA
chemical_list: D056804:Biofuels; D017931:DNA Primers; D044602:Cellulases; D043366:Cellulose 1,4-beta-Cellobiosidase
keywords: Cellobiohydrolase; Cellotriohydrolase; Exocellulase; Orpinomyces; Rumen fungus