2.2.3. Bile resistance
The ability of the strains to grow in the presence of bile (w/v)
was determined according to the method of Vinderola and
Reinheimer (2003). Each strain grown overnight was inoculated
(2% v/v) into appropriate broth with 0.06%, 0.125%, 0.25%, 0.5% and
1% of bile (w/v) (SigmaeAldrich). Cultures were incubated at 37 C
and, after 24 h, optical density at 600 nm (OD600) was measured
and compared to a control culture (without bile salts). The results
were expressed as the percentage of growth compared to the
control. Assays were carried out in triplicate.