Probiotics are alive and nonpathogenic microorganisms that have beneficial effects on their host’s health. Traditional dairy products have been used for many centuries among the natives and are the main source of potentially probiotic bacteria. In this study a total 38 lactic acid bacteria strain were isolated by preliminary screening in PBS with pH=3. The second step was in vitro test and determining their potential as probiotic. Therefore, resistance to low pH 2.5 and evaluation of 0.3 %bile salt tolerance was performed. Results showed that all isolates were able to grow at low pH and were divided to four groups according to their growth delay in bile salt (0.3%). Identification of isolates was followed by biochemical and physiological tests and 12 Lactobacillus isolates were located in tree groups including Lactobacillus sakei, Lactobacillus casei and Lactobacillus plantarum. And 26 Enterococcus isolates werelocated in four groups including Enterococcus durans, Enterococcus faecium, Enterococcus faecalis and Enterococcus avium. Finally, antimicrobial activity of three different Lactobacillus and four different Enterococcusisolates (according to biochemical and morphological tests) were tested in pH=4(culture pH) and 6.5(neutralized pH) against three pathogenic bacteria including E.coli strain PTCC 1399, Yersinia entercolitica ATCC 1159 and Listeria innocua DSMZ 20649 by agar well diffusion method. All of tested isolates showed inhibitory zone against pathogenic bacteria in pH 4, but two Enterococcus isolates and two Lactobacillus isolates showed inhibitory zone in pH 6.5. In conclusion, present study showed that traditional dairy products of these regions can be used as a good source of potentially probiotic bacteria.
