title: Production of xylooligosaccharides by immobilized His-tagged recombinant xylanase from Penicillium occitanis on nickel-chelate Eupergit C.
abstract: Penicillium occitanis xylanase 2 expressed with a His-tag in Pichia pastoris, termed PoXyn2, was immobilized on nickel-chelate Eupergit C by covalent coupling reaction with a high immobilization yield up to 93.49 %. Characterization of the immobilized PoXyn2 was further evaluated. The optimum pH was not affected by immobilization, but the immobilized PoXyn2 exhibited more acidic and large optimum pH range (pH 2.0-4.0) than that of the free PoXyn2 (pH 3.0). The free PoXyn2 had an optimum temperature of 50 °C, whereas that of the immobilized enzyme was shifted to 65 °C. Immobilization increased both pH stability and thermostability when compared with the free enzyme. Time courses of the xylooligosaccharides (XOS) produced from corncob xylan indicated that the immobilized enzyme tends to use shorter xylan chains and to produce more xylobiose and xylotriose initially. At the end of 24-h reaction, XOS mixture contained a total of 21.3 and 34.2 % (w/w) of xylobiose and xylotriose with immobilized xylanase and free xylanase, respectively. The resulting XOS could be used as a special nutrient for lactic bacteria.
authors.affiliation: Unité Enzymes et Bioconversion, Ecole Nationale d'Ingénieurs de Sfax, Université de Sfax, route de Soukra, 3038, Sfax, Tunisia, dorra_driss@yahoo.fr.
authors.forename: Dorra
authors.initials: D
authors.lastname: Driss
authors.forename: Anissa
authors.initials: A
authors.lastname: Haddar
authors.forename: Raoudha
authors.initials: R
authors.lastname: Ghorbel
authors.forename: Semia Ellouz
authors.initials: SE
authors.lastname: Chaabouni
mesh_terms: D001709:Biotechnology; D002614:Chelating Agents; D004187:Disaccharides / Q000096:biosynthesis; D043364:Endo-1,4-beta Xylanases / Q000378:metabolism*; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000235:genetics / Q000378:metabolism; D005285:Fermentation; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D005965:Glucuronates / Q000096:biosynthesis* / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D009532:Nickel; D009844:Oligosaccharides / Q000096:biosynthesis* / Q000737:chemistry; D010407:Penicillium / Q000201:enzymology* / Q000235:genetics; D010843:Pichia / Q000201:enzymology / Q000235:genetics; D011108:Polymers; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D013696:Temperature; D014312:Trisaccharides / Q000096:biosynthesis; D014990:Xylans / Q000378:metabolism; D003313:Zea mays
chemical_list: D002614:Chelating Agents; D004187:Disaccharides; D004800:Enzymes, Immobilized; D005656:Fungal Proteins; D005965:Glucuronates; D009844:Oligosaccharides; D011108:Polymers; D011994:Recombinant Proteins; D014312:Trisaccharides; D014990:Xylans; C570991:xylooligosaccharide; C515044:xylotriose; D009532:Nickel; C065843:Eupergit C; D043364:Endo-1,4-beta Xylanases; C004173:xylobiose