title: Cloning and overexpression of the xylitol dehydrogenase gene from Bacillus pallidus and its application to L-xylulose production.
abstract: The xylitol dehydrogenase gene (xdh) of Bacillus pallidus was cloned and overexpressed in Escherichia coli using pQE60 vector, for the first time. The open reading frame of 759 bp encoded a 253 amino acid protein with a calculated molecular mass of 27,333 Da. The recombinant xylitol dehydrogenase (XDH) was purified to homogeneity by three-step column chromatography, producing a single SDS-PAGE band of 28 kDa apparent molecular mass. The enzyme exhibited maximal activity at 55 °C in glycine-NaOH buffer pH 11.0, with 66% of initial enzyme activity retained after incubation at 40 °C for 1 h. In further application of the recombinant bacterium to L-xylulose production from xylitol (initial concentration 5%) using a resting cell reaction, 35% L-xylulose was produced within 24 h. This result indicates that this recombinant XDH is applicable in the large-scale production of L-xylulose.
authors.affiliation: Rare Sugar Research Center, Kagawa University, Kagawa, Japan. goro@ag.kagawa-u.ac.jp
authors.forename: Goro
authors.initials: G
authors.lastname: Takata
authors.forename: Wayoon
authors.initials: W
authors.lastname: Poonperm
authors.forename: Kenji
authors.initials: K
authors.lastname: Morimoto
authors.forename: Ken
authors.initials: K
authors.lastname: Izumori
mesh_terms: D001407:Bacillus / Q000201:enzymology* / Q000235:genetics; D003001:Cloning, Molecular / Q000379:methods*; D050542:D-Xylulose Reductase / Q000096:biosynthesis / Q000235:genetics* / Q000302:isolation & purification; D004926:Escherichia coli; D007218:Industrial Microbiology / Q000379:methods; D007700:Kinetics; D014996:Xylulose / Q000096:biosynthesis*
chemical_list: D014996:Xylulose; D050542:D-Xylulose Reductase