Bacterial community dynamics and physicochemical characteristics in natural fermentation of jiang-shui, a traditional food made in northwest China.

BACKGROUND

Chinese jiang-shui is fermented food without salt. In consideration of the few studies of the bacterial community and dynamics of jiang-shui fermentation, the aim of this study was to investigate the microbial diversity and dynamics of jiang-shui fermentation using high-throughput sequencing (HTS), denaturing gradient gel electrophoresis (DGGE) and the culture-dependent method.

RESULTS

The culture-dependent method showed that pathogenic bacteria (Staphylococcus aureus, Salmonella and Escherichia coli) and yeast mainly existed in the early stage and lactic acid bacteria dominated until the end stage. HTS and DGGE revealed that Serratia marcescens, Serratia sp., Lactobacillus curvatus, Lactococcus lactis, uncultured bacterium and Bacillus thuringiensis started the fermentation, followed by the middle stage with Lactococcus lactis, Weissella sp. and Bacillus arthracis as the predominant species. The end stage was characterized with Lactobacillus pentosus, Weissella cibaria and Weissella sp. as the major bacteria.

CONCLUSIONS

The results showed that genera Serratia, Lactococcus, Weissella and Lactobacillus dominated the whole process of jiang-shui fermentation. This study provided a good analysis of the bacterial changes of jiang-shui fermentation, and future studies should consider the relationships among the sensory characteristics, microbial communities and metabolites. © 2019 Society of Chemical Industry.