FIG. 6.

Comparison of the EDF responses of various E. coli strains. E. coli strains MC4100relA⁺, K-38, MG1655, and W3110 were grown to mid-logarithmic phase (OD₆₀₀ of 0.6) (2.5 × 10⁸ cells/ml). Duplicate samples were removed and diluted to 3 × 10⁴ cells/ml in preheated supernatant of a dense culture of MC4100relA⁺ (WT) (A), with chemically synthesized EDF in concentrations of 0.01 μg/ml (B) or 0.05 μg/ml (C). After incubation without shaking at 37°C for 10 min, rifampin (10 μg/ml) was added, and the culture was incubated without shaking at 37°C for an additional 10 min. For the rest of the experiment, see Materials and Methods.