title: Single-step purification and characterization of an extreme halophilic, ethanol tolerant and acidophilic xylanase from Aureobasidium pullulans NRRL Y-2311-1 with application potential in the food industry.
abstract: An extracellular xylanase from Aureobasidium pullulans NRRL Y-2311-1 produced on wheat bran was purified by a single-step chromatographic procedure. The enzyme had a molecular weight of 21.6kDa. The optimum pH and temperature for xylanase activity were 4.0 and 30-50°C, respectively. The enzyme was stable in the pH range of 3.0-8.0. The inactivation energy of the enzyme was calculated as 218kJmol-1. The xylanase was ethanol tolerant and kept complete activity in the presence of 10% ethanol. Likewise, it retained almost complete activity at a concentration range of 0-20% NaCl. In general, the enzyme was resistant to several metal ions and reagents. Mg2+, Zn2+, Cu2+, K1+, EDTA and β-mercaptoethanol resulted in enhanced xylanase activity. The Kmand Vmaxvalues on beechwood xylan were determined to be 19.43mgml-1and 848.4Uml-1, respectively. The enzyme exhibits excellent characteristics and could, therefore, be a promising candidate for application in food and bio-industries.
authors.affiliation: Department of Food Engineering, Ege University, 35100 Bornova, Izmir, Turkey. Electronic address: sirma.yegin@ege.edu.tr.
authors.forename: Sirma
authors.initials: S
authors.lastname: Yegin
mesh_terms: D001203:Ascomycota / Q000201:enzymology*; D004795:Enzyme Stability; D000431:Ethanol; D019649:Food Industry; D005656:Fungal Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D008670:Metals; D008970:Molecular Weight; D055049:Salt Tolerance; D014990:Xylans / Q000378:metabolism*; D014995:Xylosidases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D005656:Fungal Proteins; D008670:Metals; D014990:Xylans; D000431:Ethanol; D014995:Xylosidases
keywords: Aureobasidium pullulans NRRL Y-2311-1; Biochemical characterization; Extremophilic xylanase; Single-step purification; Thermodynamic parameters