Changes in microbial community during Chinese traditional soybean paste fermentation

Summary Chinese soybean pastes have been widely used as condiments for hundreds of years in Asian countries. However, little research has been conducted on the microbiol population in the fermentation process. The present study investigated the changes in microbiol community during the 12 weeks fermentation of natural Chinese soybean pastes with polymerase chain reaction–denaturing gradient gcl electrophoresis. Bacillus megaterium, Lactobacillus plantarum, L. fermentum, B. amyloliquefaciens, and two uncultured bacteria were predominant strains during fermentation. DGGE analysis also identified the presence of Candida humilis , Kluyveromyces lactis , Zygosaccharomyces rouxii , and Williopsis saturnus. In the industrial production of Chinese fermented soybean paste, starter cultures only contained Z. rouxii and L. plantarum. However, our results showed that more microbes are involved in the natural fermentation of Chinese soybean paste.