基于DGGE方法分析低氯化钠浓度对发酵白菜原核微生物群落结构的影响

为了探究氯化钠浓度对发酵白菜体系中微生物群落结构的影响。以4%、6%和8%氯化钠浓度发酵白菜,通过DGGE(denaturing gradient gel electrophoresis)方法及Quantity One软件分析原核微生物群落结构;通过回收DGGE电泳中荧光强度强、不同时间差异的电泳带,经克隆后测定碱基序列、与Gen Bank库序列对比鉴定。结果表明6%氯化钠浓度发酵白菜微生物多样性指数H(Shannon)、丰富度指数R(Species Richness)在发酵全过程中低于4%、8%组,均匀度指数E(Species Evenness)较4%、8%组的稳定。说明氯化钠浓度6%的发酵泡菜在整个发酵期微生物群落结构相对稳定且微生物种类小于氯化钠浓度4%、8%组。从DGGE电泳带荧光强度和存在的时间可知:在氯化钠浓度6%的发酵白菜体系中,Leuconostoc citreum(柠檬明串珠菌)、Uncultured bacterium(非培养细菌)、Leuconostoc mesenteroides(肠系膜明串珠菌)是白菜发酵中期、后期的优势微生物,Leuconostoc citreum(柠檬明串珠菌)、Leuconostoc mesenteroides(肠系膜明串珠菌)是乳酸菌。氯化钠浓度4%和8%发酵白菜中乳酸菌未成为优势微生物。说明氯化钠浓度6%较4%和8%发酵白菜原核微生物群落的变化接近于自然发酵蔬菜微生物变化规律,研究结果表明6%氯化钠浓度有利于白菜的发酵。 

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.