FIG. 2.

Effects of copper and hydrogen peroxide on growth. Overnight cultures were diluted 1:500 in TSB with different concentrations of CuSO₄ (A) or H₂O₂ (C) and incubated at 37°C with shaking. Cell growth was monitored by measuring optical density at 600 nm for 18 h. Growth curves with 2.5 mM CuSO₄ (B) and 1.5 mM H₂O₂ (D) are shown. Overnight cultures were diluted 1:500 in TSB with 1.5 mM H₂O₂ or 2.5 mM CuSO_4. Cell growth was monitored by measuring absorbance at 600 nm at various intervals of incubation at 37°C with shaking. Symbols: ⧫, wild type; ▪, mco mutant; ▴, mco complemented strain. Each point represents the mean value ± standard deviation (represented by bar) of three experiments.