Identification of Biological Wort Turbidity Caused by Microbial Contamination of Gairdner Barley

作者：Zhang Tianxue; Xu Peng; Sun Jun; Xu Kai; Sun Lihua; Qian Zhu; Qiu Ran; Zhao Changxin^*

来源：Journal of the American Society of Brewing Chemists, 2009, 67(1): 33-37.

DOI：10.1094/ASBCJ-2008-1212-01

• Aspergillus flavus
• Biological turbidity
• Gairdner barley
• Isolation and purification
• Turbidity-inducing protein

This study investigated the wort turbidity caused by microbial contamination of barley. One microbial strain isolated from Gairdner barley increased wort turbidity up to 31.9% and prolonged wort filtration time 2.67 times longer than that of the control experiment. Using morphological observation and 26S rDNA sequence alignment, the strain was identified as Aspergillus flavus. From the strain, a remarkable wort turbidity-inducing protein (WTIP) was isolated by gel-exclusion chromatography (Sephadex G-25) and purified by ion-exchange chromatography (DEAE-52 cellulose). Purified WTIP enabled wort turbidity to increase 39% (in EBC units) with the addition of 0.2 mg/L; the relative molecular weight was estimated at 80 kDa using SDS-PAGE analysis.

• 出版日期2009
• 单位大连工业大学