title: Immobilization of His-tagged recombinant xylanase from Penicillium occitanis on nickel-chelate Eupergit C for increasing digestibility of poultry feed.
abstract: Recombinant xylanase 2 from Penicillium occitanis expressed with an 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. Thermodynamically, increase in enthalpy and free energy change after covalent immobilization could be credited to the enhanced stability. Immobilized xylanase could be reused for 10 consecutive cycles retaining 60% of its initial activity. It was found to be effective in releasing reducing sugar from poultry feed. Immobilization on Eupergit C is important due to its mechanical resistance at high pH and temperature. Hence, considerable stability and reusability of bound enzyme may be advantageous for its industrial application.
authors.affiliation: Unité Enzymes et Bioconversion; Ecole Nationale d'Ingénieurs de Sfax; Université de Sfax; Sfax, Tunisia.
authors.forename: Dorra
authors.initials: D
authors.lastname: Driss
authors.affiliation: Laboratory of Electro-Mechanic Systems (LASEM); National Engineering School of Sfax (ENIS); University of Sfax; Sfax, Tunisia.
authors.forename: Zied
authors.initials: Z
authors.lastname: Driss
authors.affiliation: Unité Enzymes et Bioconversion; Ecole Nationale d'Ingénieurs de Sfax; Université de Sfax; Sfax, Tunisia.
authors.forename: Fatma
authors.initials: F
authors.lastname: Chaari
authors.affiliation: Unité Enzymes et Bioconversion; Ecole Nationale d'Ingénieurs de Sfax; Université de Sfax; Sfax, Tunisia; Unité de service commun bioréacteur couplé à un ultrafiltre; Ecole Nationale d'Ingénieurs de Sfax; Université de Sfax; Sfax, Tunisia.
authors.forename: Semia Ellouz
authors.initials: SE
authors.lastname: Chaabouni
mesh_terms: D043364:Endo-1,4-beta Xylanases / Q000378:metabolism*; D005656:Fungal Proteins / Q000378:metabolism*; D005965:Glucuronates / Q000096:biosynthesis*; D009844:Oligosaccharides / Q000096:biosynthesis*; D010407:Penicillium / Q000201:enzymology*
chemical_list: D005656:Fungal Proteins; D005965:Glucuronates; D009844:Oligosaccharides; D043364:Endo-1,4-beta Xylanases
keywords: Ni-Eupergit C; Penicillium occitanis; immobilization; poultry feed; thermodynamic; xylanase