title: Partial characterization of xylanase produced by Caldicoprobacter algeriensis, a new thermophilic anaerobic bacterium isolated from an Algerian hot spring.
abstract: To date, xylanases have expanded their use in many processing industries, such as pulp, paper, food, and textile. This study aimed the production and partial characterization of a thermostable xylanase from a novel thermophilic anaerobic bacterium Caldicoprobacter algeriensis strain TH7C1(T) isolated from a northeast hot spring in Algeria. The obtained results showed that C. algeriensis xylanase seems not to be correlated with the biomass growth profile whereas the maximum enzyme production (140.0 U/ml) was recorded in stationary phase (18 h). The temperature and pH for optimal activities were 70 °C and 11.0, respectively. The enzyme was found to be stable at 50, 60, 70, and 80 °C, with a half-life of 10, 9, 8, and 4 h, respectively. Influence of metal ions on enzyme activity revealed that Ca(+2) enhances greatly the relative activity to 151.3 %; whereas Hg(2+) inhibited significantly the enzyme. At the best of our knowledge, this is the first report on the production of xylanase by the thermophilic bacterium C. algeriensis. This thermo- and alkaline-tolerant xylanase could be used in pulp bleaching process.
authors.affiliation: Laboratory of Cellular and Molecular Biology (Microbiology group), Faculty of Biology, University of Science and Technology Houari Boumediene, Bab Ezzouar, Algiers, Algeria.
authors.forename: Khelifa
authors.initials: K
authors.lastname: Bouacem
authors.forename: Amel
authors.initials: A
authors.lastname: Bouanane-Darenfed
authors.forename: Nawel
authors.initials: N
authors.lastname: Boucherba
authors.forename: Manon
authors.initials: M
authors.lastname: Joseph
authors.forename: Mohammed
authors.initials: M
authors.lastname: Gagaoua
authors.forename: Wajdi
authors.initials: W
authors.lastname: Ben Hania
authors.forename: Mouloud
authors.initials: M
authors.lastname: Kecha
authors.forename: Said
authors.initials: S
authors.lastname: Benallaoua
authors.forename: Hocine
authors.initials: H
authors.lastname: Hacène
authors.forename: Bernard
authors.initials: B
authors.lastname: Ollivier
authors.forename: Marie-Laure
authors.initials: ML
authors.lastname: Fardeau
mesh_terms: D000462:Algeria; D003013:Clostridium / Q000201:enzymology*; D043364:Endo-1,4-beta Xylanases / Q000737:chemistry* / Q000302:isolation & purification*; D004789:Enzyme Activation; D004795:Enzyme Stability; D045482:Hot Springs / Q000382:microbiology*; D006863:Hydrogen-Ion Concentration; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D043364:Endo-1,4-beta Xylanases