Health Benefit Characterization of Dominant Lactobacilli in Traditional Doogh

The aim of our study was the characterization and evaluation of isolated lactic acid bacteria(LAB)  from traditionally produced Iranian Doogh and detection of the probable probiotic characteristics of the analyzed bacteria. We isolated 13 gram-positive and catalase-negative strains from traditionally produced Doogh and yoghurt. These strains and three control strains were investigated for anti-pathogenicity, hemolytic activity, antibiotic resistance, pH resistance and resistance against gastro enzymes in comparison to two established probiotic control strains. Identification was done by Biochemical API test and 16S rDNA sequencing methods. Eight strains had an observable inhibitory effect on bacillus cereus. No strains had hemolytic activities. 90% of isolates showed sensitivity to at least 7 of the 16 tested antibiotics, while just 15% had an intermediate sensitivity to Cloxacillin and Danofloxacin. 16 tested isolates were able to survive at pH 3 within 24 hours in phosphate buffer. 3 of the 16 Isolates suvived in simulated gastric condition for more than 2 hours at pH 2 and for 24 hours at pH 8. All identified strains were lactic acid bacteria belonging to Lactobacillus spp and one P. acidlactici. The composition of these strains might account for the specific sensorial and health benefits as well as stability of traditional Iranian Doogh.