Screening And Functional Research Of Lactic Acid Bacteria In Some Traditional Fermented Foods

Intestinal flora plays an important role in body physiological functions such as promoting body nutrition absorption,energy supply and fat metabolism.The Lactic acid bacteria are known as the vital probiotics in maintaining the micro-ecological balance of the human intestines and improving the immunity of the body.The Lactic acid bacteria were isolated and purified from traditional fermented food,and its ability to resist acid and bile salt,inhibit bacteria,adhere to IEC-6 cells and regulate intestinal flora were studied.The main results were as follows:1 64 strains of lactic acid bacteria were isolated from 15 traditional fermented food samples,which were Al,A7,A9,A18,A20,A22,A28,B3,B17,B19,B22,and had strong acid producing ability.The acidity of A9 was 118.60°T after 24h fermentation.The survival rate of 6 strains in the pH 3 artificial gastric juice was over 60%on further study,and the survival rate of 12 strains in 0.5%bile salt environment was more than 10%,and 6 strains survived in both artificial gastric juice of pH 3 and the 0.5%bile salt environment,the survival rate of which is significantly higher than those of other strains(P<0.05).2 The diameter of 6 strains of Escherichia coli,Clostridium difficile and Salmonella were greater than 15.65mm,The inhibition ability of Al,A5,A9,B8 and B14 was stronger than the three pathogenic bacteria,while the inhibition ability of A9 was significantly higher than that of other strains(P<0.05).The Al,A5,A9 and B8 had strong adhesion ability to IEC-6 cells was studied,and the number of adhesion was greater than 9/cell.The A9 was moderately resistant to benzoxicillin and erythromycin,and was sensitive to amoxicillin,gentamicin,Amikacin,erythromycin,cefazolin,cefuroxime,cefotaxime,kanamycin,lincomycin and A9 was identified as Lactobacillus plantarum(L.plantarum)by 16S rRNA sequencing.3 The disorder of intestinal flora in rats was caused by continuous intragastric administration of 3 days hydrochloride lincomycin,the number of bifidobacteria spp.and Lactobacillus spp.decreased significantly in the intestine(P<0.05),and the Enterococcus spp.increased significantly(P<0.05),the value of B/E decreased significantly(P<0.05),and the intestinal micro-flora were not restored in 7 days.The intervention of L.plantarum A9 significantly decreased the number of Enterococcus spp.,Clostridium spp.and Enterobacteriaceae spp.in rats(P<0.05),while the bacteriobacteria spp.,Lactobacillus spp.and bifidobacteria spp.were significantly increased(P<0.05).