Analysis and comparison of bacterial communities in two types of 'wheat Qu', the starter culture of Shaoxing rice wine, using nested PCR-DGGE

Abstract

Shaoxing rice wine, manufactured in Shaoxing region of Zhejiang Province, is the best-known Chinese rice wine. In the current study, the bacterial communities associated with two types of 'wheat Qu', the Shaoxing rice wine starter cultures, were identified and compared using nested PCR-denaturing gradient gel electrophoresis analysis. DNA sequencing of the highly variable V3 or V9 regions of the 16S rRNA genes obtained from PCR-DGGE fingerprints identified common species related to Saccharopolyspora hordei, S. rectivirgula, Bacillus subtilis, B. amyloliquefaciens and so on. Some sequences associated with a particular type were also identified. For example, Clavibacter michiganensis and Saccharopolyspora sp. were found in the machine- but not in the human-made type, while Curtobacterium plantarum, Thermoactinomyces intermedius, T. vulqaris, B. licheniformis and Bacillus sp. were found in human- but not in machine-made type of wheat Qu. The information gathered from the present research enriches the present knowledge of Shaoxing rice wine-related bacteria, and will also facilitate the longterm objective of selecting bacterial combinations to be used as starter cultures that will more tightly regulate the fermentation process, as well as improve the quality and safety of wheat Qu. © 2012 The Institute of Brewing & Distilling.