不同香型白酒大曲微生物群落及其与风味的相关性

The relationship between microbial community and flavors of three types of Daqu

该研究基于宏基因组学技术对3种香型白酒大曲微生物群落及其功能特征进行解析,采用顶空固相微萃取气质联用(headspace solid-phase microextraction/gas chromatography-mass spectrometry)检测大曲风味物质,并通过关联性分析探究微生物与风味间的联系。结果表明3种大曲菌群结构具有显著差异,线性判别分析(linear discriminant analysis effect size,LEfSe)揭示浓香型大曲特征细菌属和真菌属为Bacillus和Lichtheimia、Saccharomyces,其中高丰度的Bacillus有利于四甲基吡嗪和2,3-丁二醇的生成;清香型大曲特征菌群以Lactobacillus、Weissella等产酸细菌属和产酯真菌属Pichia组成,使得清香型大曲中酯类风味物质含量显著高于其他大曲。酱香型大曲特征细菌属和真菌属分别为Desmospora、Saccharopolyspora和Byssochlamys、Aspergillus等。基于KEGG(Kyoto Encyclopedia of Genes and Genome)功能注释可知3种大曲参与碳水化合物代谢与氨基酸代谢的功能基因最多且均存在显著差异。在3种大曲中,清香型大曲微生物在碳水化合物代谢比例最高,而酱香型大曲中氨基酸代谢比例最高。该研究阐明了3种大曲微生物菌群结构差异以及核心产香微生物,为后续筛选功能微生物与开发功能型强化酒曲提供了理论基础。

In this study,the structure and functional characteristics of microbial communities of three different flavor-style Daqu were investigated through metagenomics technology,then the metabolic composition were detected by HS-SPME-GC-MS(headspace solid-phase microextraction/gas chromatography-mass spectrometry).The relationship between microorganisms and flavors were illustrated by Spearman’s correlation analysis.Results showed that there were significant differences in microbial community between the three kinds of Daqu.The LEfSe analysis revealed that the characteristic bacterial and fungal genera of strong-flavor Daqu were Bacillus,Lichtheimia and Saccharomyces,among which,the high abundance of Bacillus was beneficial to the generation of tetramethylpyrazine and 2,3-butanediol.The characteristic community of the light-flavor Daqu was composed of acid-producing bacterial genera(Lactobacillus,Weissella,etc.)and the ester-producing fungal genera(Pichia),which made the content of esters in light-flavor Daqu significantly higher than those of other two kinds.The characteristic bacterial and fungal genera of sauce-flavor Daqu were Desmospora,Saccharopolyspora and Byssochlamys,Aspergillus,etc.Based on the KEGG function annotation,it could be seen that functional genes involved in carbohydrate metabolism and amino acid metabolism which constituted the most,were significant differences between three kinds of Daqu.Besides,light-flavor Daqu microorganisms were most active in carbohydrate metabolism,while sauce-flavor Daqu were most active in amino acid metabolism.This study clarified the differences in the microbial structure of three types of Daqu and analyzed the core aroma-producing community,providing a theoretical basis for the subsequent screening of functional microorganisms and the development of functional fortified Daqu.