Purification, characterization, and molecular cloning of the xylanase from Streptomyces thermovulgaris TISTR1948 and its application to xylooligosaccharide production

Publication date: Available online 23 April 2016 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): Pinpanit Boonchuay, Shinji Takenaka, Ampin Kuntiya, Charin Techapun, Noppol Leksawasdi, Phisit Seesuriyachan, Thanongsak Chaiyaso A crude xylanase preparation from Streptomyces thermovulgaris TISTR1948 was able to hydrolyze KOH-treated corncob and to produce bioactive xylooligosaccharides (XOs). A thermostable cellulase-free endo-xylanase from strain TISTR1948 was purified 15.0-fold from the crude preparation, with a recovery yield of 13.0%. On SDS-PAGE, the purified enzyme had an apparent molecular mass of 46.2kDa. The N-terminal and internal amino acid sequences were determined and the cloned xylanase gene were sequenced. The 1,434-bp gene encodes a protein with a predicted molecular mass of 46,976Da. The deduced amino acid sequence had a high degree of identity with the sequences of GH 10 xylanases from Streptomyces spp. The purified xylanase was highly stable within a pH range of 4.0–11.5 and was thermostable within a temperature range of 50–70°C. The activity of the enzyme reached a maximum at 65°C; the enzyme’s half-life was 90min at 70°C. Enzymatic activity was enhanced in the presence of metal ions, Ca2+, Co2+, and Mn2+ but almost completely inhibited by Hg2+, Pb2+, and SDS. The Km and Vmax values of the enzyme with beechwood xylan as the substrate were 37.55μM and 303.03U/mg, respectively. The crude, partially purified, and puri...
Source: Journal of Molecular Catalysis B: Enzymatic - Category: Biochemistry Source Type: research