FIG 1.

Effects of bile salts on V. cholerae biofilm formation. (A) Structures of select bile salts. Cholate can be dehyroxylated at the 7α position to form deoxycholate or conjugated with taurine to form taurocholate. (B) V. cholerae was inoculated into glass tubes and allowed to form biofilms for 24 h at 22°C. Biofilms of cultures grown in the presence of deoxycholate (DC), cholate (CC), glycocholate (GC), or taurocholate (TC) were quantified with crystal violet staining, and data are presented as OD₅₇₀ values. (C) Expression of vpsA during formation of WT V. cholerae biofilms in the presence of 1 mM DC and TC for 18 h, as measured by the β-galactosidase assay. Data are means and standard deviations (SD) from three independent experiments. NS, no significance; *, P < 0.05; **, P < 0.005; ***, P < 0.0005; ****, P < 0.0001.