title: Production, purification, and characterization of a cellulase-free thermostable endo-xylanase from Thermoanaerobacterium thermosaccharolyticum DSM 571.
abstract: This is the first report describing the cloning, expression, and characterization of a putative thermostable, cellulase-free xylanase (XYN) from the thermophilic bacterium Thermoanaerobacterium thermosaccharolyticum DSM 571. The temperature and pH values for optimal enzyme activity of XYN were found to be 65 °C and pH 6.5, respectively. The XYN activity was apparently enhanced by Co(2+), Mn(2+), and Tween 60 and significantly inactivated by Al(3+), Cu(2+), Zn(2+), and SDS. The K m and V max values of XYN for the hydrolysis of beechwood xylan were 2.1 mg/ml and 222.1 U/mg, respectively. The k cat values of XYN for beechwood xylan at the optimal temperature and pH values were 481.4 s(-1). XYN represents an attractive candidate for use in the large-scale production of xylooligosaccharides (XOs) from forest residues because it is an endo-xylanase capable of degrading xylan.
authors.affiliation: College of Chemical Engineering, Nanjing Forestry University , Jiangsu Key Lab of Biomass-Based Green Fuels and Chemicals, Nanjing, Jiangsu, 210037, China, xunlee@163.com.
authors.forename: Xun
authors.initials: X
authors.lastname: Li
authors.forename: Hao
authors.initials: H
authors.lastname: Shi
authors.forename: Huaihai
authors.initials: H
authors.lastname: Ding
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.forename: Fei
authors.initials: F
authors.lastname: Wang
mesh_terms: D003001:Cloning, Molecular; D043364:Endo-1,4-beta Xylanases / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D015870:Gene Expression; D006863:Hydrogen-Ion Concentration; D008670:Metals / Q000737:chemistry; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D013379:Substrate Specificity; D046950:Thermoanaerobacterium / Q000201:enzymology* / Q000235:genetics; D014990:Xylans / Q000737:chemistry*
chemical_list: D008670:Metals; D011994:Recombinant Proteins; D014990:Xylans; D043364:Endo-1,4-beta Xylanases