Traditional Soybean Paste In Microbial Diversity Ananlysis

Analysis of the traditional fermented foods, microbial flora has been isolated from microbial culture as a precondition, this method has certain limitations, and the operation is cumbersome, heavy workload, and the current level can not be100%of the strains in which the real separation out. The application of molecular biology methods enable us to study the microbial diversity at the genetic level. Compared with traditional culture methods, molecular biology techniques can reveal the regularity of the ebb and flow of all kinds of microorganisms in the fermentation process to explore the population structure of microorganisms in food fermentation process, showing obvious superiority. Since the PCR-DGGE technology since1993Muyzer to introduce the field of microbial ecology, has become an important tool in the study of microbial diversity and population structure in recent years has been widely used in traditional fermented foods, microbial flor.In this study, through traditional methods and the DGGE method we had these conclutions as follows:Through traditional methods we isolated53microorganisms, after bacteria staining and microscopy to observe the macroscopic morphology of colonies identified as combination of the following categories:bacteria37,9yeast and7fungi were screened out, three of them are salt-tolerant bacteria: xj007, xj008, jm004, the highest salt tolerance is15%.DGGE electrophoresis by bacteria, there are A, B, E, F four distinct bands, where C band only in samples4,7,8, appeared. In yeast, there are A, D, F three distinct bands, band B only appear in the3,8samples, indicating that even traditional fermented soybean paste, resulting in a geographical differences microbial diversity.Purified out by some bacteria, fungi, respectively, and18S rDNA sequence of16S rDNA amplification, sequenced by sequencing, the sequences compared in the NCBI and build the phylogenetic tree obtained: xj001is Pediococcus, xj008is Lactobacillus planturam, jm002as Saccharomyces cerevisiae, jm004is Candida spp.; mj001is Aspergillus spp., mj005is Mucor spp.. Pediococcus spp., Aspergillus spp.,Tetragenococcus halophilus Lactobacillus delbrueckii were not detected in the DGGE analysis. Lactobacillus sakei,Streptococcus thermophilus, Williopsis saturnus not screened by the traditional methods.