FIG 4.

MICs of C. metallidurans mutant strains. Cells from a first preculture were diluted 20-fold into a second preculture with fresh TMM, cultivated at 30°C with shaking until the stationary phase was reached, diluted 100-fold with fresh TMM, and streaked onto TMM agar plates with increasing concentrations of the test substance. The MIC was determined after incubation at 30°C for 4 days and is the lowest concentration preventing the formation of colonies. The strains are indicated on the top. (A) EDTA; (B) zinc; (C) cadmium. The last two panels in each group have different scales for the y axes, which are additionally highlighted by the gray bars in panel C3.