FIGURE 4.

Exogenous H₂S promotes the growth of the E. coli (ΔiscS) mutant under anaerobic conditions. (A) The effect of different concentrations of Na₂S on the growth of wild-type E. coli under anaerobic conditions. (B) The effect of different concentrations of Na₂S on the growth of the E. coli (ΔiscS) strain under anaerobic conditions. (C) The effect of 500 μM Na₂S on the growth of wild-type E. coli under anaerobic conditions. (D) The effect of 500 μM Na₂S on the growth of the E. coli (ΔiscS) mutant under anaerobic conditions. (E) The effect of different concentrations of Na₂S on the growth of wild-type E. coli under aerobic conditions. (F) The effect of different concentrations of Na₂S on the growth of the E. coli (ΔiscS) strain under aerobic conditions. (G) The effect of 500 μM Na₂S on the growth of wild-type E. coli under aerobic conditions. (H) The effect of 500 μM Na₂S on the growth of the E. coli (ΔiscS) mutant under aerobic conditions. The data points and errors show the means ± SD of four independent experiments. ^∗p < 0.05, ^∗∗p < 0.01, ^∗∗∗p < 0.001, versus the control group. Samples without Na₂S were used as a control.