Antimicrobial activity of isolated Lactobacillus plantarum and Lactobacillus fermentum with probiotic potential from some traditional food against most intestinal pathogens

Background: Probiotics are live bacteria and yeasts that are good for our health, especially our digestive system and have an effective role in increasing host resistance , especially in case of disease which caused by intestinal pathogens, so in this study we investigated antimicrobial activity of isolated Lactobacillus plantarum and Lactobacillus fermentum from traditional samples of milk ,yogurt and pickle ,against standard strains or strains which confirmed by genetic sequences like E.coli O157 H7 ,Salmonella enteritidis ATCC14028 , Shigella flexnerri ATCC12022 , Yersinia enterocolitica ATCC 11010. Methods: Biochemical identification tests for 90 samples of traditional foods (30 samples for each), was done by culturing and growthing on MRS broth and agar in candle jar, catalas, carbohydrate fermentation and production of gas from glucose tests. Probiotic potential of these strains was done by heat, acid and bile tolerance tests. Genetics verifying test was done by sequencing of 16srDNA genes. Antimicrobial activity of cell-free supernatant assayed by well- diffusion method. Results: Results shown probiotic lactobacilli isolated from milk (10%), yoghurt (2.2%) and pickle (1%) were respectively. Frequency of Lactobacillus fermentum (22.2%) is more than Lactobacillus plantarum (18.9%). Both of probiotic strains of Lactobacillus plantarum and Lactobacillus fermentum shown the most antimicrobial effect with pathogenic bacteria: Shigella flexnerri ATCC12022, Salmonella enteritidis ATCC14028, E. coli O157 H7 and Yersinia enterocolitica ATCC 11010, respectively. Conclusion: By having good inhibitory effect of lactobacilli against some intestinal pathogenes , we can use from probiotics and probiotic products daily and increase our healthy against more disease ,also traditional dairy and pickles products can use as an important source of probiotic lactobacilli.

کلیدواژه ها:

Probiotic ، Traditional food ، Lactobacilli ، Antimicrobial test