Phenotypic and Genotypic investigation of Lactobacillus spp Isolated from breast milk

BACKGROUND AND OBJECTIVESBreast milk is the combination of bioactive compounds and microflora that promote newborn’s proper growth, gut flora, and immunity. Thus, it is always considered the perfect food for newborns.However, it had been presumed to be germ-free, human milk now believed to contain many bacteria including. One of the most important genera of probiotic bacteria found in milk is Lactobacillus. The aim of the present study was to further analysis of Lactobacilli present in human milk.MATERIALS AND METHODS۴۷ milk samples were collected and cultured on MRS agar. The identity of isolates was further inspected using PCR reaction. The potential probiotic capacity was analyzed by the ability of the strains to withstand bile salt and acidic condition. Moreover ,pathogen antagonistic effect of the isolates was assessed using agar spot test on ten prominent bacterial pathogens. To determine the nature of the pathogen killing mechanism of the isolated Cell free suspension was subjected to proteolytic enzymes and catalase enzyme.RESULTS AND DISCUSSION۷۵۴ bacterial colonies isolated from milk samples. ۵۰ Out of ۱۷۸ randomly-picked colonies were immune to acidic condition and Bile salt.۳۴ of these isolates were proved to Lactobacillus genus. Most of the isolated Lactobacilli were able to prevent the growth of pathogens. A major percentage of these isolated prevented the growth of the pathogen by producing organic acid.CONCLUSIONConsequently, these study suggests that human milk contains potential probiotic which may play a major role in infant’s health Thus, the human-originated LAB strains are being furthermore characterized to exploit their probiotic and therapeutic potential towards specific human welfare in the form of customized functional foods and infant formulas.

کلیدواژه ها:

Human milk ، Probiotic ، Lactobacillus ، Bacteriocin