对新、老窖泥的微生物菌群结构和进化关系,及其与酒醅发酵过程中己酸、丁酸产生的相关性进行了分析,发现窖泥中主体己酸菌为梭菌纲下的己酸菌属微生物,该属下的3种己酸菌在窖泥中均有发现,且以乳酸利用型己酸菌为主体;而通常被认为是窖泥中主体己酸菌的梭菌纲梭菌属微生物克氏梭菌在新老窖泥中的丰度均较低。该研究对浓香型白酒酿造窖泥中的己酸菌类型进行了初步的解析,相关分析方法与结果将为研究窖泥中己酸菌的酿造功能及应用价值奠定基础。
Fermentation within mud-built pit results in strong-aroma type Baijiu (Chinese liquor), of which the typical flavors come from the metabolites of microbes in pit mud. Caproic acid, the most important volatile component during the fermentation process of strong-aroma type Baijiu, is positively related with the concentration of ethyl caproate. However, the species of caproate-producing microbes in pit mud were not well understood, leading to the deficiency in deciphering the functions of pit mud microbes. In this study, the structure and phylogenic correlation of microbiotas in new- and aged-pit muds were analyzed and the correlation between the microbiota structure and the metabolites (caproate and butyrate) in fermented yellow water were investigated. The results showed that the dominant caproate-producing microbes were the species of the genus Caproicproducens. Whereas Clostridium kluyveri, the traditional recognized caproate-producing microbe, was rarely found within new- and aged-pit muds. This study preliminarily illustrated the dominant caproate-producing microbes in pit muds, and the corresponding approaches and results lay a foundation for further analysis of the functions of caproate-producing microbe as well as its applications.
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