Partial characterization of β‐ d‐xylosidase from wheat malts. Issue 3 (13th April 2015)

• Record Type: Journal Article
• Authors: Chai, Yanan; Jin, Yuhong; Du, Jinhua; Li, Jia; Zhang, Kaili
• Is Part Of: Journal of the Institute of Brewing. Volume 121:Issue 3(2015)
• Page Start: 338
• Page End: 342
• Publication Date: 2015-04-13
• Subjects: Brewing -- Periodicals; 663.305
• DOI: 10.1002/jib.228
• Languages: English
• ISSNs: 0046-9750

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p>Arabinoxylans (AXs) from wheat malts potentially affect beer quality and production. <italic>β</italic>‐ <sc>d</sc>‐Xylosidase is a key enzyme that degrades the main chains of AXs to <ext-link ext-link-type="uri" xlink:href="app:ds:product" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink">produce</ext-link> xylose. This study performed a partial characterization of <italic>β</italic>‐ <sc>d</sc>‐xylosidase from wheat malts. The optimal temperature was 70 °C and the enzyme exhibited excellent thermostability, that is, residual activities were 92.6% at 60 °C for 1 h. The enzyme was stable over a pH range of 3.0–6.0 and showed optimum activity at pH 3.5 and 4.5. Kinetic parameters <italic>K</italic><sub>m</sub> and <italic>V</italic><sub>max</sub> of wheat malt <italic>β</italic>‐ <sc>d</sc>‐xylosidase against <italic>p</italic>‐nitrophenyl‐xyloside were 1.74 mmol L<sup>−1</sup> and 0.76 m <sc>m</sc> min<sup>−1</sup>, respectively. The enzyme activity was severely inhibited by Cu<sup>2+</sup>, moderately inhibited by Mn<sup>2+</sup>, Mg<sup>2+</sup>, Al<sup>3+</sup>, Ca<sup>2+</sup>, Ba<sup>2+</sup> and Na<sup>+</sup> and mildly inhibited by Fe<sup>3+</sup> and Fe<sup>2+</sup>. The partial enzymatic characterization achieved in this study can be used as a theoretical basis for purifying <italic>β</italic>‐ <sc>d</sc>‐xylosidase from wheat malts. Copyright © 2015 The Institute of Brewing & Distilling</p> </abstract>