浓香型白酒酒醅发酵过程中微生物群落结构演替及其与理化指标相关性

Structural Succession of Microbial Communities in Fermented Grains for Nongxiangxing Baijiu during the Fermentation Process and Its Correlation with Physicochemical Indicators

为明确浓香型白酒酒醅中微生物群落结构的演替规律及其潜在功能,通过高通量测序技术解析酒醅微生物群落在发酵过程中的动态变化,分析不同发酵节点的微生物群落与理化指标的相关性,并采用PICRUSt分析对酒醅中微生物群落的功能进行预测。结果表明:厚壁菌门(Firmicutes)、变形菌门(Proteobacteria)、放线菌门(Actinobacteriota)、子囊菌门(Ascomycota)、担子菌门(Basidiomycota)是酒醅中的优势菌门,浓香型酒醅中微生物以乳杆菌属(Lactobacillus)、芽孢杆菌属(Bacillus)、葡萄球菌属(Staphylococcus)、高温放线菌属(Thermoactinomyces)、哈萨克斯坦酵母属(Kazachstania)、威克汉姆酵母属(Wickerhamomyces)、青霉属(Penicillium)、假丝酵母菌属(Candida)、曲霉属(Aspergillus)、季也蒙酵母属(Meyerozyma)和德巴利酵母属(Debaryomyces)为主,Lactobacillus、Kazachstania、Wickerhamomyces占绝对优势;相关性分析表明,还原糖、淀粉含量与8个细菌属呈显著正相关(P<0.05),酸度、水分含量与10个细菌属呈显著负相关(P<0.05),部分真菌与理化指标显著相关;PICRUSt分析表明,不同发酵节点的功能酶相对丰度差异显著,酒醅中的优势微生物参与糖酵解、酸代谢、乙醇合成形成完整的代谢链,说明酒醅微生物群落的演替是不同发酵节点代谢差异的主要原因。本研究分析了酒醅微生物的演替规律及其在发酵过程中参与的代谢,为白酒酿造微生物的代谢机制研究提供一定理论基础。

In order to clarify the succession pattern and potential functions of the microbial communities in fermented grains for Nongxiangxing baijiu,high-throughput sequencing was used to investigate the dynamic change of microbial community structure,and the correlations between microbial community structure and physicochemical indicators were analyzed at different fermentation stages.Phylogenetic Investigation of Communities by Reconstruction of Unobserved States(PICRUSt)was used to predict the potential functions of microbial communities in fermented grains.The results showed that Firmicutes,Proteobacteria,Actinobacteriota,Ascomycota,and Basidiomycota were the dominant phyla in fermented grains.The dominant genera were Lactobacillus,Bacillus,Staphylococcus,Thermoactinomyces,Kazachstania,Wickerhamomyces,Penicillium,Candida,Aspergillus,Meyerozyma,Debaryomyces,with Lactobacillus,Kazachstania and Wickerhamomyces being the absolutely dominant ones.The contents of reducing sugar and starch showed a significantly positive correlation with 8 bacterial genera(P<0.05).Acidity and moisture content showed a significantly negative correlation with 10 bacterial genera.Some fungi were significantly correlated with physicochemical indicators.PICRUSt analysis showed that the relative abundance of functional enzymes was significantly different at different fermentation stages,and the dominant microorganisms in fermented grains participated in glycolysis,acid metabolism and ethanol synthesis to form a complete metabolic chain,indicating that the microbial community succession of fermented grains could be the major reason for the differences in metabolism at different fermentation stages.The findings of this study would provide a theoretical basis for the study of the metabolic mechanisms of microorganisms used for baijiu brewing.