Abstract: In this work, the differences in the composition and diversity of the bacterial community in environmental samples from each of seven repeated rounds of Maotai-flavor liquor fermentation in 2018 in Maotai town were systematically studied by high-throughput sequencing technology combined with mathematical statistical analysis. The results showed that the diversity and richness of bacterial flora in the fermentation environment were high at each round, but differed with the number of fermentation rounds. The structure and composition of the dominant phyla and genera were similar among rounds, and the dominant bacterial community structure remained stable. Totally 19 phyla and 396 genera were detected from all samples. Proteobacteria, Firmicutes, Bacteroidetes and Actinobacteria were the dominant phyla. There were 14 dominant bacterial genera identified, mainly Sphingobacterium, Enterobacter, Pantoea, Pseudomonas, Escherichia-Shigella, Staphylococcus. By partial least squares discriminant analysis (PLS-DA) combined with Adonis and PERMANOVA, we found that the structure of the bacterial community was significantly different at the genus level but not at phylum level among rounds, and the main differential bacterial genera included Lentibacillus, Enterobacter, Escherichia-Shigella, Cronobacter, and Stenotrophomonas. The findings obtained in this study provide scientific evidence for understanding the structure of bacterial microflora in the brewing environment of Maotai-flavor liquor in Maotai town and the brewing mechanism of high-quality Maotai-flavor liquor.

Key words: Maotai-flavor liquor; high-throughput sequencing; bacterial microflora; fermentation environment