title: Purification and characterization of a thermostable xylanase from Saccharopolyspora pathumthaniensis S582 isolated from the gut of a termite.
abstract: An extracellular thermostable xylanase produced by Saccharopolyspora pathumthaniensis S582 was purified 167-fold to homogeneity with a recovery yield of 12%. The purified xylanase appeared as a single protein band on SDS-PAGE, with a molecular mass of 36 kDa. The optimal temperature and pH of the xylanase were 70 °C and 6.5. The enzyme was stable within a pH range of 5.5-10.0. It retained its activity after incubation at 50 °C for 2 h. Its half lives at temperatures of 60 and 70 °C were 180 and 120 min respectively. Hydrolysis of beechwood xylan by the xylanase yielded xylobiose and xylose as major products. The enzyme acted specifically on xylan as an endo-type xylanase, and exhibited a K(m) value of 3.92 mg/mL and a V(max) value of 256 µmol/min/mg. Enzyme activity was completely inhibited by Hg(2+), and was stimulated by Rb(+) and Cs(+). The xylanase gene was cloned from genomic DNA of Saccharopolyspora pathumthaniensis S582 and sequenced. The ORF consisted of 1,107 bp and encoded 368 amino acid residues containing a putative signal peptide of 23 residues. This xylanase is a new member of family (GH) 10 that shows highest identity, of 63.4%, with a putative xylanase from Nocardiopsis dassonvillei subsp. dassonvillei.
authors: Department of Applied Biological Chemistry, Faculty of Agriculture, Shizuoka University, Shizuoka, Japan.
authors: Kanokkorn
authors: K
authors: Sinma
authors: Khwanchai
authors: K
authors: Khucharoenphaisan
authors: Vichien
authors: V
authors: Kitpreechavanich
authors: Shinji
authors: S
authors: Tokuyama
mesh_terms: D000595:Amino Acid Sequence; D000821:Animal Feed; D000818:Animals; D003001:Cloning, Molecular; D043364:Endo-1,4-beta Xylanases / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D004795:Enzyme Stability; D005110:Extracellular Space / Q000201:enzymology; D029964:Fagus / Q000737:chemistry; D041981:Gastrointestinal Tract / Q000382:microbiology*; D006868:Hydrolysis; D020049:Isoptera / Q000382:microbiology*; D007700:Kinetics; D008969:Molecular Sequence Data; D016930:Saccharopolyspora / Q000166:cytology / Q000201:enzymology*; D013379:Substrate Specificity; D013696:Temperature; D014990:Xylans / Q000378:metabolism
chemical_list: D014990:Xylans; D043364:Endo-1,4-beta Xylanases