Abstract: This research aimed at investigating the structure and diversity of the bacterial community in Guizhou shui-douchi at three different fermentation stages by Illumina MiSeq high-throughput sequencing technology and also at isolating and identifying the dominant bacteria. The results showed that a total of 296 063 valid data and 1 124 operational taxonomic units (OTU) were obtained from the three samples. A total of six phyla and 21 genera were annotated. At the phylum level, the abundance of Firmicutes increased with the increase in fermentation time, while the abundance of Proteobacteria decreased. At the genus level, the abundance of Bacillus increased. Due to the addition of antibacterial ingredients such as salt and spices, the number of bacterial species presented a declining trend after post-fermention for 24 hours. In addition, four strains with high protease activity were obtained using an automated?mass spectrometry microbial identification system?(VITEK MS) and were identified as Bacillus subtilis, Bacillus amyloliquefaciens, and Bacillus cereus, respectively. This study may provide a guidance for the standardization and safety control of Guizhou shui-douchi.

Key words: shui-douchi; high-throughput sequencing technology; diversity; fermentation stage; strain isolation and identification