FIG 4.

Physiology of the ΔtrhA_EC mutant supports defective membrane energetics. (A) E. coli WT and ΔtrhA_EC mutant cells were plated on the center of a soft agar (0.3%) plate. The plates were imaged after 18 h of incubation at 28°C. (B) The total ATP production of stationary-phase E. coli WT and ΔtrhA_EC mutant cells was measured as luminescence relative light units (RLU). Data represent the ATP content from three biological replicates with three technical replicates. Error bars represent the standard deviation. (C) MICs of E. coli WT and the ΔtrhA_EC strain for different antibiotics. MIC values represent the average concentration of antibiotic (in μM) that observably inhibited the growth of three to five biological replicates with three technical replicates each. (D) Biofilm production of E. coli WT and the ΔtrhA_EC mutant. Cultures were grown overnight in 12-well plates containing a sterile microscope slide. Biofilms that adhered to the air-liquid interface of a coverslip were stained with crystal violet and quantified at OD₅₉₀. The OD₅₉₀ was normalized to cell growth as OD₆₀₀. Points represent quantifications of biofilm produced from three biological replicates with three technical replicates. Error bars represent the standard deviation.