Dynamic changes in bacterial community structure during soy sauce fermentation

Techniques such as 16S rDNA polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) fingerprinting and phylogenetic analysis were used to reveal the dynamic changes in bacterial community structure during a high-salt-diluted fermentation of guangdong soy sauce. Total bacterial DNA was extracted from the samples and touchdown PCR was performed to amplify the V3 region of 16S rDNA. Subsequently, based on DGGE fingerprints, the specific gel bands were excised, sequenced, and analyzed using Basic Local Alignment Search Tool (BLAST). The DGGE fingerprints showed that various types of bacterial communities existed in the initial fermentation period, but only few survived in the later stages. The evolutionary pattern of the microbial community structure during soy sauce fermentation progressed from complex to simple, which demonstrated that the growth of microorganisms was inhibited by the conditions of fermentation. The sequencing identified the bacterial strains as Weissella cibaria and uncultured Enterobacter sp. with highest similarity, followed by Tetragenococcus halophilus, Weissella paramesenteroides, Citrobacter freundii, Enterobacter aerogenes, and Enterobacter sp. BF1-8. ©, 2015, South China University of Technology. All right reserved.