Effect of concentration of sodium chloride in Chinese paocai on prokaryotic microbial community based on DGGE

In order to explore the impacts of microbial communities in fermented pickle system, the experiment was conducted by taking 4%, 6% and 8% as sodium chloride concentration to ferment pickle. Using DGGE ( denaturing gradient gel electrophoresis) method and software of Quantity One to analyse Prokaryotic microbial community structure. And recycling the electrophoretic bands with strong fluorescence intensity and different time difference in DGGE which is measured to base sequence after cloning to be compared and identified with Gene Bank sequence.The results showed that microbial diversity index ( H) , richness index ( R) of sauerkraut fermented by 6% sodium chloride concentration in the fermentation process was lower than 4% 's and 8% 's, the index of evenness ( E) was more stable than 4% 's and 8% 's. It showed the microbial community structure of sauerkraut fermented by 6% sodium chloride concentration in the fermentation period of microbial community structure was relatively stable and its microbial species is far less than 4% and 8% ‘s. From the DGGE electrophoretic band fluorescence intensity and the time of existence, it was found that Leuconostoc citreum, Uncultured bacterium, Leuconostoc mesenteroides are dominant bacteria in the fermented cabbage system with 6% sodium chloride concentration. Leuconostoc citreum and Leuconostoc mesenteroides belong to lactic acid. The lactic acid bacteria with 4% and 8% sodium chloride concentration in fermented cabbage did not become a dominant microorganism. It shows that the changes of prokaryotic microbial community in fermented cabbage with 6% concentration sodium chloride are closer to natural fermented vegetables' microbial variation comparing with 4% and 8% concentration sodium chloride, so the research indicated that 6% sodium chloride concentration is more beneficial to the fermentation of cabbage.