Isolation and Identification of Lactobacilli From Cheese, Yoghurt and Silage by 16S rDNA Gene and Study of Bacteriocin and Biosurfactant Production

Background: the lactobacilli belong to lactic acid bacteria, whose primary fermentationend product from sugars is lactic acid and that is why foods are conserved. lactic acidbacteria have been used for millennia in the production of silage. therefore, they are anindispensable part of intestinal microflora in human and animals.objectives: this research meant to isolate lactic acid bacteria with significant effectsfrom different environments.materials and methods: in this study, heterofermentative lab were isolated fromcheese, yoghurt and corn silage in broujerd ,iran. the standard biochemical methodswere applied. acid tolerance was studied by exposure to acidic pbs and growth in bilesalt was measured by the spectrophotometric method. the isolated bacteria were studiedfor antagonistic effects on environment isolated e.coli, bacteriocin and biosurfactantproduction. bacterial dna was extracted, and amplified by pcr method.results: the 3 isolates from cheese, yoghurt and silage were effective against isolatede.coli and could produce biosurfactants. phylogenic relationships of the 3 potential candidateswere determined comparing the 16sr dna gene sequences, they were found tobe as 3 isolates of lactobacillus buchneri, l.brevis and l.kefiri that were effective on the isolatede.coli from environment.conclusions: it was found that the isolated bacteria produced biosurfactants that had agreat potential for different industries.