The Diversity Of Microbial From Natual Fermented Food Suan-Cai By DGGE

Suan-cai is fermented foodstuff produced through fermentation of vegetable products by beneficial microorganism. The fermentation method influences the diversity of microbes (bacteria and fungi) present, and different groups of microorganisms are responsible for fermentation at different stages of production, this produces its unique flavor. Using (polymerase chain reaction-denaturing gradient gel electrophoresis PCR-DGGE) techniques have proved to be effective techniques for quantifying microbial community structure and diversity, It can provide a scientific basis for adopt pure culture technology industrial production suan-cai products.In this paper, thirteen natural fermented suan-cai liquid were respectively collected from in Shenyang Liaoning province and Ulanhot Inner Mongolia region. Through the optimization method of extracting DNA, total DNA was rapidly extracted using the CTAB method. The V3 region of the 16S rRNA gene of bacteria were amplified for DGGE analysis. And with different fermentation suan-cai as the research object. Twenty five suan-cai in different fermentation period were collected. The V3 region of the 16S rRNA gene of bacteria, and the D1/D2 region of the 26S rRNA gene of fungi were amplified, and DGGE. Further study the microflora during natural fermentd of suan-cai. The results of the reseach are shown below.1、This experiment optimizes the DGGE condition method. Total DNA was extracted from suan-cai by CTAB method, The DGGE gel was stained by Genefinder staining, The optimal denaturing gradient of bacterial DGGE was determined by 35-50%2、According to 16S rDNA sequence analysis, the isolates were grouped in 4 genera and 10 species of the natural fermented suan-cai liquid from Shenyang Liaoning province, Lactobacillus sakei and Lactobacillus plantarum were the dominant bacteria in Shenyang Liaoning province.3、The isolates were grouped in 5 genera and 14 species of the natural fermented suan-cai liquid from Ulanhot Inner Mongolia region, Lactobacillus fermentum and Lactobacillus plantarum were the dominant bacteria in Ulanhot Inner Mongolia region.4、Lactobacillus plantarum were the dominant bacteria of two regions. The microbial species were indentify in Ulanhot natural fermented suan-cai liquid were more rich than Shenyang. Using the PCR-DGGE technique allowed us to identify bacteria species previously not recorded using traditional culture-based techniques and these included Lactobacillus paralimentarius and Lactobacillus alimentarius.5、In this paper. DGGE fingerprint of suan-cai in different fermentation period indicated that the bacterium was abundant, while fungi was relatively few in suan-cai. Lactobacillus and uncultured bacteria were the dominant bacteria during suan-cai fermentation. Throughout the fermentation process in suan-cai, the early active bacterium was Leuconostoc sp, Lactobacillus acidophilus, and Lactobacillus gasseri, then were Lactobacillus fermentum, Lactobacillus plantarum, Lactobacillus coryniformis were the predominant microflora in the middle and later periods. Pseudomonas and Bacillus was existed in end-fermentation stages. Using the PCR-DGGE technique allowed us to identify bacteria species previously not recorded using traditional culture-based techniques and these included Lactobacillus farraginis. Debaryomyces hansenii, Candida tropicalis, Penicillium expansum, Penicillium olsonii were the dominant fungi during suan-cai fermentation. Beside, we also detected Candida albicans, Penicillium solitum.Therefore, PCR-DGGE technology can accurately detected microbial and its dynamic change of natural fermented suan-cai, it provides an advanced technical means for effective analysis of complex microbial community in suan-cai. It also identify bacteria species previously not recorded using traditional culture-based techniques, for separation of some Lactic acid bacteria that can promote fermentation, It can provide a scientific basis for industrial production of suan-cai.