Abstract:In order to quantitatively analyze the differences in bacterial structure and composition types in fermented mustard based on different fermentation processes and salt consumption，high-throughput sequencing analysis technology was used to compare the composition and diversity of bacterial community structure in V4-V5 region of 16S rDNA sequence of bacteria existing in three fermented mustard groups.The results showed that the microbial diversity between groups A and B was similar，while the diversity of group C with the lowest salt content was higher than that of groups A and B.The three fermentation groups were mainly dominated by Firmicutes，Proteobacteria，Actinobacteria，and Bacteroidetes in terms of bacterial composition.Based on the genus level，Lactobacillus，Corynebacterium，Brevibacterium，Acinetobacter and Halomonas were the main dominant genera in the three fermentation groups.Among them，the bacterial colony composition of samples A and B was basically the same，but there was a significant difference in bacterial colony composition compared to sample C.In order to screen high-quality industrial strains that were more suitable for direct fermentation of mustard，a total of 9 strains were collected from each of the three mustard fermentation groups，which met the requirements of Gram positive staining results，negative catalase identification，and no spore production.Three strains，Z-2，Z-6，and Z-9，were selected based on the acid and high salt resistance of the control strains，The excellent strains with fermentation broth pH values between 3.7 and OD values above 1.0 in a 16% salt concentration fermentation broth were subjected to physiological and biochemical tests and 16S rDNA sequencing technology analysis.The results showed that Z-2 was Lactobacillus pentosus，Z-6 was Lactobacillus plantarum，and Z-9 was Weisseria helleniensis，making them suitable for industrial production of pickled mustard.