title: Characterization of a recombinant thermostable xylanase from deep-sea thermophilic Geobacillus sp. MT-1 in East Pacific.
abstract: A novel xylanase-producing thermophilic strain MT-1 was isolated from a deep-sea hydrothermal field in east Pacific. A xylanase gene encoding 331 amino-acid peptide from this isolate was cloned and expressed in Escherichia coli. The recombinant xylanase exhibited maximum activity at 70 degrees C and had an optimum pH of 7.0. It was active up to 90 degrees C and showed activity over a wide pH ranging from 5.5 to 10.0. The crude xylanase presented similar properties in temperature and pH to those of the recombinant xylanase. The recombinant xylanase was stable in 1 mM of enzyme inhibitors (PMSF, EDTA, 2-ME or DTT) and in 0.1% detergents (Tween 20, Chaps or Triton X-100), whereas, it was strongly inhibited by sodium dodecyl sulfate (SDS) (1 mM). In addition, its catalytic function was stable in the presence of Li(+), Na(+) or K(+). However, it was strongly inhibited by Ni(2+), Mn(2+), Co(2+), Cu(2+), Zn(2+), Cd(2+), Hg(2+) and Al(3+) (1 or 0.1 mM). The K (m) and V (max) of the recombinant xylanase for oat spelt xylan were calculated to be 1.579 mg/ml and 289 micromol/(min x mg), respectively. Our study, therefore, presented a rapid overexpression and purification of xylanase from deep-sea thermophile aimed at improving the enzyme yield for industrial applications and scientific research.
authors.affiliation: School of Life Sciences, Xiamen University, Xiamen 361005, People's Republic of China.
authors.forename: Suijie
authors.initials: S
authors.lastname: Wu
authors.forename: Bin
authors.initials: B
authors.lastname: Liu
authors.forename: Xiaobo
authors.initials: X
authors.lastname: Zhang
mesh_terms: D001406:Bacillaceae / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification*; D001426:Bacterial Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D003001:Cloning, Molecular; D004591:Electrophoresis, Polyacrylamide Gel; D043364:Endo-1,4-beta Xylanases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004795:Enzyme Stability; D004926:Escherichia coli / Q000235:genetics; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008670:Metals / Q000494:pharmacology; D010140:Pacific Ocean; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D012623:Seawater / Q000382:microbiology*; D012967:Sodium Dodecyl Sulfate / Q000494:pharmacology; D013696:Temperature; D014990:Xylans / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D004791:Enzyme Inhibitors; D008670:Metals; D011994:Recombinant Proteins; D014990:Xylans; D012967:Sodium Dodecyl Sulfate; D043364:Endo-1,4-beta Xylanases