The fatty acid mimetic 2CCA-1 differs in the mode of action from antibacterial fatty acids. (A) D39ΔfakB3 (BHN2024) and (B) D39ΔfabT (BHN2032) treated with 2CCA-1 (100 μM and 50 μM) and DMSO (1% [vol/vol]) as a compound solvent control in early logarithmic phase (arrows indicate time of treatment). Corresponding treatments of wild-type D39 are shown as averages for reference (dotted lines). (C) Comparison of the lysis inducing activity of free fatty acids of different saturation degree and acyl chain length with 2CCA-1 at their respective MlytC concentration on wild-type D39 (see also Fig. S6C to G) with lauric acid (12:0; 500 μM), stearic acid (18:0; 500 μM), oleic acid (18:1Δ9; 100 μM), linoleic acid (18:2Δ9,12; 100 μM), and 2CCA-1 (3 μM). (D) Treatment of wild-type D39 30 min after entering stationary phase with 2CCA-1 (50 μM; 16× MlytC), linoleic acid (18:2Δ9,12; 100 μM; 1× MlytC), nisin (4 μg/ml; 8× MIC), and penicillin dissolved in DMSO or water (0.25 μg/ml; 8× MIC).