贮存过程中大曲原核微生物多样性及土味素含量变化规律

Prokaryotic microbial diversity and geosmin content in the storage process of Daqu

通过对不同贮存时期大曲的微生物群落结构的分析,进一步阐述了大曲的贮存过程的必要性。采用MiSeq高通量测序方法,鉴定出原核微生物119个属。其3种大曲相对丰度靠前的优势菌属主要为乳酸菌属、芽孢杆菌属、明串珠菌属、魏斯氏菌属、链霉菌属、短杆菌属等。随着贮存时间的推移,3种大曲的物种多样性都处于上升趋势。在各个阶段高温曲的物种丰度和多样性都高于清茬曲和红心曲,说明高温曲的制曲工艺使得微生物生长更活跃。分析3种大曲中链霉菌与土味素的含量变化趋势,在贮存3个月时,两者的含量相对较低。因此,从异味控制的角度来看,大曲贮存3个月左右的时间更利于白酒风味的形成。

The necessity of storage of Daqu was clarified by analyzing microbial community structure of Daqu dur- ing different storage periods. 119 genera of prokaryotic microbe were identified using the method of MiSeq high- throughput sequencing. Dominant microbes which have a relatively higher abundance in three kinds of Daqu mainly were Lactobacillus , Bacillus, Leuconostoc , Weissella , Streptomyces , Brevibacterium etc. Species diversity of three kinds of Daqu presented a rising tendency as time goes on. Species diversity and abundance of Gaowen Daqu were higher than those of Qingcha Qu and Hongxin Qu. It indicated that the craft process of Gaowen Daqu was more suit- able for the growth of microbes. Both the content of geosmin and abundance of Streptomyces in the three kinds of Daqu were found obviously lower in the third month of storage compared with the initial stage. Therefore, Daqu storing over three month was conductive to the control of off-odor.