| Kimchi is a unique food with a long history. Mustard, beans, bamboo shoots, ginger, peppers, radishes and fish, duck, pork be made traditional fermented kimchi in Guangxi. In fermentation process, the lactic acid bacteria produce a variety of physiologically active substances, which make Kimchi become a comprehensive functional food. In this study, both culture-dependent and culture-independent methods based on the metagenomics technology were used to examine the lactic acid bacteria diversity of fermented kimchi. Purpose is to reflect the beneficial bacteria and established the dominant strains of in traditional fermented kimchi, to reveal the true face of traditional fermented foods and provide a strong theoretical foundation and technical support for Guangxi, but also for the future of the traditional fermentation of the food processing industry research important microbial resources. The bacteria were sifted and isolated from the samples of pickles juice and yogurt. According to the culture of phenotypic characteristics and under the physiological and biochemical characteristics, and the reference to "common bacteria identified manual system" to determine its biological categories. Strains were attributable to the Lactobacillus (5), Streptococcus (2), Tetraggenococcus (1), a total of five species. The effectives of three methods for extraction of the total bacterial DNA from different fermentation kimchi were compared.The result showed that the Beadbeater mechanical method, SDS repeated freezing method could obtain low DNA, the improved method of lysozyme combine digestion and pyrolysis could obtain highest DNA yield and was the best one for the DNA purity.According to the PCR-DGGE analysis, the DNA extracted by the lysozyme combine digestion and pyrolysis method presented more diverse lactic acid bacteria community than that of the others methods. 10 DGGE band spectrum were cloned and sequenced, obtained seven different sequences at last. Mostly sequences were similar to the 16SrDNA sequence of lactic acid bacteria. Which band A and Lactobacillus delbrueckii subsp have close genetic relationship,100% similarity; band B and Lactobacillus sp have close genetic relationship,96% similarity; bandsD and Planococcaceae bacterium have close genetic relationship,100% similarity; band E and Lactobacillus Versmoldensis have close genetic relationship,100% similarity; band F and Lactobacillus acidophilus have close genetic relationship,100% similarity... |
