Microbial Succession Law of the Daqu-Making Environment in Jiang-Flavor Daqu

Jiang-flavor Daqu is the starter used in the production of Jiangxiangxing Baijiu, as it is the primary source of microorganisms. The production of Jiangxiangxing Baijiu heavily relies on the use of Jiang-flavor Daqu, wherein the quality of the latter is intricately associated with the surrounding environment during the Daqu-making process. The objective of this study was to investigate the evolution pattern of microbial communities in the Daqu-making environment as the Daqu room application period increased and determine their role in shaping Jiang-flavor Daqu microbial communities. There was a certain level of overlap observed in the dominant microbial genera between the Daqu-making environment of Jiang-flavor Daqu and Jiang-flavor Daqu itself. Consequently, this may explain the close relationship observed in both bacterial life activities. And there was also a strong correlation between the ground and air fungal communities in the Daqu-making house during various usage periods. Furthermore, the composition of microbial communities in the air, the composition of microbial communities in the ground, the bacterial function in the air, and the bacterial function in the ground displayed varying degrees of similarity. However, it is worth noting that the microbial community structure undergoes changes with the gradual increase in the usage time of the fermentation chamber, leading to differences in microbial markers between various fermentation chambers. Most importantly, the quantity of bacteria, molds, and yeasts in the production environment during the initial use stage of the Daqu room was generally advantageous. Additionally, the microbial community in Jiang-flavor Daqu primarily originates from the initial production environment in the Daqu room. The study demonstrated that the microbial community structure in the Daqu room during the early stage significantly contributes to the formation of the microbial community structure in Jiang-flavor Daqu. These findings provide novel insights for improving the quality of Jiang-flavor Daqu.