Probiotics are live microorganisms which upon ingestion in sufficient concentrations can exert health benefits to the host. actually, the useful effects of probiotics are applied by equilibrating the beneficial gut microflora. therefor before a probiotic can benefit human health, it must fulfill several criteria such as the ability to tolerate acid and bile salts, that’s how to survive passage through the upper gastro-intestinal tract and arrive alive at its site of action. new probiotic strains should be resistant to these sever condition of human gastrointestinal tract.
The aim of this study was to find out the ability of bile and acid tolerance of bacillus subtilis isolated from camel milk in semnan. the acid tolerance test was evaluated by culturing in mrs broth under ph values (3.5, 4.5 and 5.5) and for bile resistance test in mrs broth containing bile concentration (0.3, 0.5 and 1%) was prepared. then, the bacterial growth was determined by measuring absorption with a spectrophotometer at 600nm during 24 hours incubation at 37c.
Based on the growth outcomes, bacillus subtilis showed suitable resistance to ph and different concentrations of bile salts.
Results of this study suggest that b. subtilis isolated from camel milk has potential as a probiotic strain.