浓香型白酒发酵过程中酒醅微生物群落结构解析及其与风味物质的相关性

Microbial Community and Its Correlation with Flavor Compounds of Fermented Grains during Strong-flavor Baijiu Fermentation

以浓香型白酒连续发酵的酒醅样品为研究对象,基于高通量测序技术分析白酒发酵过程微生物群落组成及动态变化,采用气相色谱-质谱联用(gas chromatography-mass spectrometry,GC-MS)法测定酒醅样品中的挥发性风味物质,并分析微生物群落与风味物质的相关性。结果表明,发酵过程中酒醅样品细菌的丰富度和多样性高于真菌,厚壁菌门(Firmicutes)和子囊菌门(Ascomycota)分别是丰度最高的优势细菌门和真菌门。平均相对丰度大于1%的优势细菌属有乳杆菌属(Lactobacillus)、蚤蝇属(Levilinea)和普雷沃菌属(Prevotella)等;优势真菌属有酵母菌目的未分类属(unclassified Saccharomycetales)、嗜热真菌属(Thermomyces)和曲霉属(Aspergillus)等。微生物与主要风味物质的相关性研究发现,在浓香型白酒发酵过程中,与主要风味物质相关的微生物包括8个菌属,分别为Thermomyces、Naumovozyma、酵母属(Saccharomyces)、Lactobacillus、醋酸杆菌(Acetobacte)、梭状芽孢杆菌属(Clostridium)、假丝酵母属(Candida)和Aspergillus。

This study analyzed the composition and dynamic changes of the microbial community during the Baijiu fermentation using high-throughput sequencing technology based on fermented grain samples from the fermentation of strong-flavor Baijiu.Gas chromatography-mass spectrometry (GC-MS) was employed to determine the volatile flavor compounds in the fermented grains and analyze the correlation between the microbial community and flavor compounds.The results showed that the abundance and diversity of bacteria in the fermented grains were higher than at the phylum level,Firmicutes and Ascomycota were the dominant bacteria and fungi with the highest abundance,respectively.Dominant bacterial genera with an average relative abundance greater than 1% included Lactobacillus,Levilinea,and Prevotella.Dominant fungal genera included unclassified Saccharomycetales,Thermomyces,and Aspergillus.The correlation analysis between microorganisms and major flavor compounds revealed that eight genera were associated with the main flavor compounds during the fermentation of strong-flavor Baijiu,namely Thermomyces,Naumovozyma,Saccharomyces,Lactobacillus,Acetobacter,Clostridium,Candida,and Aspergillus.