Growth rates of P. aeruginosa WT and P. aeruginosa ΔgshA in different media. n = 3 to 5. Significance was calculated by two-way analysis of variance (ANOVA) followed by Bonferroni’s multiple-comparison test with 95% confidence interval. **, P < 0.01; ****, P < 0.0001. Error bars represent 1 standard error. GSH, glutathione; TRP, tryptone; YE, yeast extract; CDM, chemically defined medium.