Analysis On Microorganism Of Lactic Acid Bacteria In Sichuan Yibin Pickled Mustard Vein

Yibin Pickled mustard vein is one of four Sichuan salted and preserved vegetable, which is popular because of it’s special favour and rich nutrition.However, it has been restricted for the traditional production process.This research focused on analyzing Lactic acid bacteria (LAB) in it, which is supposed to study the microflora of LAB and find something useful for manufacture.The conclusions are as follwed:(1) Six kinds of selective medium were used to isolate lactic acid bacteria from Sichuan Yibin pickled mustard vein.The pH of strain was lower more than4.0in MRS broth for72h and Rf values was similar to standard sample of lactic acid were selected for follow-up test.The strains were analyzed by16S rDNA PCR-RFLP with five kinds of restriction endonucleases including Msp I, HaeⅢ, TaqⅠ, HinfⅠ and Hha Ⅰ.Twelve genotypes were classed, and four were belong to F, three were H and three were J.There was only one difference genotypes in some strains, so these indicated that small dissimilar base sequence in16S rDNA could be identified by the suitable restriction endonucleases.From the results, Haelll produce seven kinds of genotypes, Mspl produced six, Hinfl produced five, Taql and Hhal generate three.And samlpes generated different kinds of fingerprint:seven, five and two, so a high genetic diversity existed in sample A.(2)16S rDNA PCR-RFLP and ERIC-PCR analysis showed that lactic acid bacteria have rich genetic diversity.Based on the fingerprint of16S rDNA PCR-RFLP and ERIC-PCR, representative strains were selected to construct the phylogenetic tree and the results showed the dominating LAB in Yibin pickled mustard vein were Lactobacillus plantarum, Eenterococcus durans and Pediococcus pentosaceus(3) Ten strains were cultivated and the result demonstrated that the optimum temperature is37℃, optimum growth pH value is about6.5.Growth began to be logarithmicphase at4h, then into the stationary phase at10h.(4) At the same time, Denaturing Gradient Gel Electrophoresis was used to analyzed the microflora of LAB. PCR-DGGE pattern profiles showed that dinersity of LAB were quite different amomg the three samples, C was the highest, B was followed, and A was least. Sequence of DGGE bands indicated that the dominating lactic acid bacteria in Yibin pickled mustard vein were Lactobacillus and Enterobacter.The results of this research revealed genetic diversity and phylogenetic position of LAB in Sichuan Yibin pickled mustard vein, LAB was comprised of Lactobacillus alimentarius, Lactobacillus plantarum, Lactobacillus casei.Eenterococcus durans, Pediococcus pentosaceus.lt laid the theoretical foundation for the development and application LAB for Yibin pickled mustard vein as direct vat starter.