title: Characterization and constitutive expression of a novel endo-1,4-β-D-xylanohydrolase from Aspergillus niger in Pichia pastoris.
abstract: A putative endo-1,4-β-D-xylanohydrolase gene xyl10 from Aspergillus niger, encoding a 308-residue mature xylanase belonging to glycosyl hydrolase family 10, was constitutively expressed in Pichia pastoris. The recombinant Xyl10 exhibited optimal activity at pH 5.0 and 60 °C with more than 50 % of the maximum activity from 40 to 70 °C. It retained more than 90 % of the original activity after incubation at 60 °C (pH 5.0) for 30 min and more than 74 % after incubation at pH 3.0-13.0 for 2 h (25 °C). The specific activity, K m and V max values for purified Xyl10 were, respectively, 3.2 × 10(3) U mg(-1), 3.6 mg ml(-1) and 5.4 × 10(3) μmol min(-1 )mg(-1) towards beechwood xylan. The enzyme degraded xylan to a series of xylooligosaccharides and xylose. The recombinant enzyme with these properties has the potential for various industrial applications.
authors.affiliation: School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China. zhengjia@csu.edu.cn
authors.forename: Jia
authors.initials: J
authors.lastname: Zheng
authors.forename: Ning
authors.initials: N
authors.lastname: Guo
authors.forename: Lishuang
authors.initials: L
authors.lastname: Wu
authors.forename: Jian
authors.initials: J
authors.lastname: Tian
authors.forename: Hongbo
authors.initials: H
authors.lastname: Zhou
mesh_terms: D001234:Aspergillus niger / Q000201:enzymology* / Q000235:genetics; D043364:Endo-1,4-beta Xylanases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004795:Enzyme Stability; D015870:Gene Expression; D005965:Glucuronates / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009844:Oligosaccharides / Q000378:metabolism; D010843:Pichia / Q000201:enzymology* / Q000235:genetics; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013696:Temperature; D014990:Xylans / Q000378:metabolism; D014994:Xylose / Q000378:metabolism
chemical_list: D005965:Glucuronates; D009844:Oligosaccharides; D011994:Recombinant Proteins; D014990:Xylans; C570991:xylooligosaccharide; D014994:Xylose; D043364:Endo-1,4-beta Xylanases