title: Purification and characterization of the xylanase produced by Jonesia denitrificans BN-13.
abstract: Jonesia denitrificans BN-13 produces six xylanases: Xyl1, Xyl2, Xyl3, Xyl4, Xyl5, and Xyl6; the Xyl4 was purified and characterized after two consecutive purification steps using ultrafiltration and anion exchange chromatography. The xylanase-specific activity was found to be 77 unit (U)/mg. The molecular weight of the Xyl4 estimated using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed a monomeric isoenzyme of about 42 kDa. It showed an optimum pH value of 7.0 and a temperature of 50 °C. It was stable at 50 °C for 9.34 h. The enzyme showed to be activated by Mn(+2), β-mercaptoethanol, and dithiothreitol (DTT) with a high affinity towards birchwood xylan (with a K(m) of 1 mg ml(-1)) and hydrolysis of oat-spelt xylan with a K(m) of 1.85 mg ml(-1). The ability of binding to cellulose and/or xylan was also investigated.
authors.affiliation: Laboratory of Applied Microbiology, Faculty of Nature Science and Life, University of Bejaia, Targa Ouzemmour, 06000, Bejaia, Algeria, boucherbanawel@yahoo.fr.
authors.forename: Nawel
authors.initials: N
authors.lastname: Boucherba
authors.forename: Mohammed
authors.initials: M
authors.lastname: Gagaoua
authors.forename: Estelle
authors.initials: E
authors.lastname: Copinet
authors.forename: Azeddine
authors.initials: A
authors.lastname: Bettache
authors.forename: Francis
authors.initials: F
authors.lastname: Duchiron
authors.forename: Said
authors.initials: S
authors.lastname: Benallaoua
mesh_terms: D000192:Actinomycetales / Q000737:chemistry* / Q000201:enzymology; D001426:Bacterial Proteins / Q000737:chemistry* / Q000302:isolation & purification; D029662:Betula / Q000737:chemistry; D002413:Cations, Divalent; D004229:Dithiothreitol / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007527:Isoenzymes / Q000737:chemistry / Q000302:isolation & purification; D007700:Kinetics; D008345:Manganese / Q000737:chemistry; D008623:Mercaptoethanol / Q000737:chemistry; D013379:Substrate Specificity; D013696:Temperature; D014990:Xylans / Q000737:chemistry; D014995:Xylosidases / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D001426:Bacterial Proteins; D002413:Cations, Divalent; D007527:Isoenzymes; D014990:Xylans; D008345:Manganese; D008623:Mercaptoethanol; D014995:Xylosidases; D004229:Dithiothreitol