title: Purification and characterization of xylitol dehydrogenase with l-arabitol dehydrogenase activity from the newly isolated pentose-fermenting yeast Meyerozyma caribbica 5XY2.
abstract: Meyerozyma caribbica strain 5XY2, which was isolated from an alcohol fermentation starter in Thailand, was found to catabolize l-arabinose as well as d-glucose and d-xylose. The highest production amounts of ethanol from d-glucose, xylitol from d-xylose, and l-arabitol from l-arabinose were 0.45 g/g d-glucose, 0.60 g/g d-xylose, and 0.61 g/g l-arabinose with 21.7 g/L ethanol, 20.2 g/L xylitol, and 30.3 g/l l-arabitol, respectively. The enzyme with l-arabitol dehydrogenase (LAD) activity was purified from the strain and found to exhibit broad specificity to polyols, such as xylitol, d-sorbitol, ribitol, and l-arabitol. Xylitol was the preferred substrate with Km=16.1 mM and kcat/Km=67.0 min-1mM-1, while l-arabitol was also a substrate for the enzyme with Km=31.1 mM and kcat/Km=6.5 min-1mM-1. Therefore, this enzyme from M. caribbica was named xylitol dehydrogenase (McXDH). McXDH had an optimum temperature and pH at 40°C and 9.5, respectively. The McXDH gene included a coding sequence of 1086 bp encoding a putative 362 amino acid protein of 39 kDa with an apparent homopentamer structure. Native McXDH and recombinant McXDH exhibited relative activities toward l-arabitol of approximately 20% that toward xylitol, suggesting the applicability of this enzyme with the functions of XDH and LAD to the development of pentose-fermenting Saccharomyces cerevisiae.
authors: Department of Industrial Biotechnology, Faculty of Agro-Industry, Prince of Songkla University, Songkhla 90112, Thailand; Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan.
authors: Wiphat
authors: W
authors: Sukpipat
authors: Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan. Electronic address: hkomeda@pu-toyama.ac.jp.
authors: Hidenobu
authors: H
authors: Komeda
authors: Department of Industrial Biotechnology, Faculty of Agro-Industry, Prince of Songkla University, Songkhla 90112, Thailand.
authors: Poonsuk
authors: P
authors: Prasertsan
authors: Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan; Asano Active Enzyme Molecule Project, ERATO, JST, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan.
authors: Yasuhisa
authors: Y
authors: Asano
mesh_terms: D050542:D-Xylulose Reductase / Q000302:isolation & purification* / Q000378:metabolism*; D000431:Ethanol / Q000378:metabolism; D005285:Fermentation; D005947:Glucose / Q000378:metabolism; D010084:Oxidation-Reduction; D010429:Pentoses / Q000378:metabolism*; D004718:Saccharomycetales / Q000201:enzymology / Q000378:metabolism*; D013401:Sugar Alcohol Dehydrogenases / Q000378:metabolism*; D013402:Sugar Alcohols / Q000378:metabolism; D014993:Xylitol / Q000378:metabolism
chemical_list: D010429:Pentoses; D013402:Sugar Alcohols; D000431:Ethanol; D013401:Sugar Alcohol Dehydrogenases; C022751:D-arabinitol dehydrogenase; D050542:D-Xylulose Reductase; D005947:Glucose; D014993:Xylitol
keywords: Alcohol fermentation starter; Broad polyol specificity; Meyerozyma caribbica; Xylitol dehydrogenase; l-Arabitol dehydrogenase