Figure 3. α-muricholic acid inhibits germination by C. difficile M68 spores.

(A) Germination of Clostridium difficile M68 spores in complex medium supplemented with taurocholic acid (TA) or (B) medium supplemented with TA and 1 mM α-muricholic acid. • 0 mM TA, ▪ 2 mM TA, ▴ 5 mM TA, ▾ 10 mM TA,♦ 20 mM TA or ○ 50 mM TA. (C) The inverse rate (1/v [sec/OD₆₀₀]), versus the inverse taurocholate concentration (1/S [mM⁻¹], was plotted. Apparent K_m values for TA alone (•) and in the presence of α-muricholic acid (▪) were determined from the linear best fit of the plotted data. (D) Hill Plot was generated to determine the apparent K_m values for each condition.