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Characterization of an ethanol‐tolerant 1,4‐β‐xylosidase produced by Pichia membranifaciens
Author(s) -
Romero A.M.,
Mateo J.J.,
Maicas S.
Publication year - 2012
Publication title -
letters in applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.698
H-Index - 110
eISSN - 1472-765X
pISSN - 0266-8254
DOI - 10.1111/j.1472-765x.2012.03297.x
Subject(s) - yeast , xylose , enzyme , hemicellulose , ethanol , pichia stipitis , fermentation , biochemistry , hydrolysis , sephadex , ethanol fuel , xylan , enzyme assay , chemistry , pichia , molecular mass , biology , pichia pastoris , recombinant dna , gene
Aims: The purification and biochemical properties of the 1,4‐β‐xylosidase of an oenological yeast were investigated. Methods and Results: An ethanol‐tolerant 1,4‐β‐xylosidase was purified from cultures of a strain of Pichia membranifaciens grown on xylan at 28°C. The enzyme was purified by sequential chromatography on DEAE cellulose and Sephadex G‐100. The relative molecular mass of the enzyme was determined to be 50 kDa by SDS‐PAGE. The activity of 1,4‐β‐xylosidase was optimum at pH 6·0 and at 35°C. The activity had a K m of 0·48 ± 0·06 mmol l −1 and a V max of 7·4 ± 0·1 μmol min −1 mg −1 protein for p ‐nitrophenyl‐β‐ d ‐xylopyranoside. Conclusions: The enzyme characteristics (pH and thermal stability, low inhibition rate by glucose and ethanol tolerance) make this enzyme a good candidate to be used in enzymatic production of xylose and improvement of hemicellulose saccharification for production of bioethanol. Significance and Impact of the Study: This study may be useful for assessing the ability of the 1,4‐β‐xylosidase from P. membranifaciens to be used in the bioethanol production process.