In order to assess bile salt tolerance of bacteria, the isolates
of Streptococcus, Lactobacillus and Bifidobacterium, were
incubated in MRS broth (pH 7.0) containing L-cysteine ·
HCl · H
2O as 0.05% concentration (w/v) at 37oC for 24 hrs
under anaerobic conditions. MRS broth was supplemented
with 0.3% (w/v) oxgall (Sigma, USA, pH 7.0). All bacteria
were inoculated as 30 µl volume and incubated at 37oC for 3
hrs. Then, bacteria were spread onto BL agar plates to
confirm the survival of bacteria and anaerobically incubated
at 37oC for 48 hrs. If colonies were formed on the BL media,
they were decided as the bacteria to have bile salt tolerance