[Resistance of Bifidobacterium sp. isolated from Iranian subjects to simulated gastric juice and bile salt]

Bifidobacteria are one of the most important probiotic bacteria and their benefits have been known since many years ago. Probiotic organisms are required to be safe, viable and metabolically active within the gastrointestinal tract and to show enough resistance against bile and gastric juice. In this research, the ability of growth and survival of 42 strains, isolated from Iranian subjects, were studied in MRS3 containing 0, 0.25, 0.5, 1 and 2% of bile salts and simulated gastric juice with pH 3. The cultured strains were incubated under anaerobic condition and at 37°C for 48 h and then the survival/growth rates were examined at 3, 6, 12 and 24 hrs. The results demonstrated that some strains had significantly high tolerance against bile salts and simulated gastric juice. The strains with high tolerance are suggested as Iranian strains for future work especially in preparing Iranian starter and bifidus products

[Identification of Bifidobacterium strains isolated from fecal samples of some Iranian subjects using 16SrRNA gene sequence analysis and PCR-based gene specific primers]

For the first time in Iran 40 strains of Bifidobacterium were isolated from faces of Iranian subjects. By using phenotypic tests, 18 isolates were identified as Bifidobacterium longum, 10 as Bifidobacterium bifidum and 1 as Bifidobacterium catenolatum. In order to validate these results and also to identify other isolates that had not been identified by phenotypic tests, 2 methods of PCR with genus-specific primers of Bif164f and Bif601r and 16SrRNA gene sequence analysis were applied. Results of PCR confirmed the obtained phenotypic identifications. Moreover by this method the 8 remaining strains were identified as Bifidobacterium species. Using sequencing 16SrRNA gene, 5 B.Longum strains were identified that had different fermentation pattern from B.Longum. Some new ribose negative Bifidobacterium longum strains were also identified. The obtained results present new strains of Bifidobacterium longum

[Identification of Bifidobacterium strains isolated from fecal samples of some Iranian subjects using 16 SrRNA gene sequence analysis and PCR-based gene specific primers]

For the first time in Iran 40 strains of Bifidobacterium were isolated from feces of Iranian subjects. By using phenotypic tests, 18 isolates were identified as Bifidobacterium longum, 10 as Bifidobacterium bifidum and one as Bifidobacterium catenolatum. In order to validate these results and also to identify other isolates that had not been identified by phenotypic tests, two methods of PCR with genus-specific primers of Bif164f and Bif601r and 16SrRNA gene sequence analysis were applied. Results of PCR confirmed the obtained phenotypic identifications. Moreover by this method the 8 remaining strains were identified as Bifidobacterium species. Using sequencing 16 SrRNA gene, 5 B. longum strains were identified that had different fermentation pattern from B. longum. Some new ribose negative Bifidobacterium longum strains were also identified. The obtained results present new strains of Bifidobacterium longum