Fig. 4: MB is inducing oxidative stress in E. coli K-12 MG1655 after light activation.

MB without photo activation (MB dark). Shown are growth curves of the reporter strain (A), final optical densities (B), YFP/CFP expression of the Pdps module over time (C), and total YFP/CFP expression (D) in response to the indicated concentration of MB. MB with photo activation (MB light). Shown are growth curves of the reporter strain (E), final optical densities (F), YFP/CFP expression of the Pdps module over time (G), and total YFP expression (H) in response to the indicated concentration of MB after photo activation. The dashed lines indicate the time point of the addition of the test substance. Shown are the results of representative experiments. The columns (D, H) represent the average results of three biological replicates (*P < 0.05; **P < 0.01; ***P < 0.001).