中高温大曲中酵母菌的分离及其在小曲酒中发酵性能初探

Isolation and identification of yeast strains from near high temperature Daqu and characterization of their fermentation performance via brewing Baijiu by purebred rice Qu

从中高温大曲中分离出酵母菌,通过制作米曲酿造小曲酒初步探究了大曲中的酵母菌在小曲酒中的发酵能力。采用稀释平板涂布法从大曲中分离纯化出酵母菌,经形态学和分子生物学鉴定确定了酵母菌的种属,并优化了米曲制作过程中原料的含水量和制曲时间。结果表明,从中高温大曲中共分离出4株酵母菌(Y1、Y2、Y3和Y4),经鉴定Y1为异常威克汉逊酵母(Wickerhamomyces anomalus),Y2为东方假丝酵母(Candida odintsovae),Y3和Y4为酿酒酵母(Saccharomyces cerevisiae)。米曲的最佳制作工艺为在原料含水量为46%(质量分数)下培养7 d。以高粱为原料,米曲和糖化酶为糖化发酵剂发酵产酒发现,4种酵母的产酒能力依次为酿酒酵母Y3>酿酒酵母Y4>异常威克汉逊酵母Y1>东方假丝酵母Y2。该研究为提高小曲酒质量和开发大曲中微生物资源提供了一条有效途径。

The yeasts were isolated from near high temperature Daqu,and their fermentation performances were initially characterized via brewing Baijiu by purebred rice Qu,a fermenting agent made from a single species of yeast.First,the yeasts were isolated by gradient dilution coating method and identified by their morphological and biological characteristics,and then the process of making purebred rice Qu was optimized,including the moisture content of materials and the fermentation time.The results showed that four kinds of yeasts were obtained from near high temperature Daqu,named as Y1,Y2,Y3 and Y4,respectively.The present study identified Y1 as Wickerhamomyces anomalus,Y2 as Candida odintsovae,Y3 and Y4 as Saccharomyces cerevisiae.We found that incubating 7 days with46%water contents were the optimal parameters in making purebred Rice Qu.About brewing Xiaoqu Baijiu,sorghum was used as a raw material while the purebred rice Qu and saccharifying enzyme were used as the saccharifying and fermenting agent.The fermentability of these four kinds of yeasts were in the order of:Saccharomyces cerevisiae Y3>Saccharomyces cerevisiae Y4>Wickerhamomyces anomalus Y1>Candida odintsovae Y2.This study provides an effective way to improve the quality of Xiaoqu Baijiu and mining the microbial resources in Daqu.