FIG. 5.

MtsR inactivation results in hypersensitivity to streptonigrin and hydrogen peroxide. (A) Sensitivity of the wild-type (NZ131) and mtsR mutant (ZE491) to streptonigrin. Bacteria were inoculated into fresh THY medium containing 0.36 μM streptonigrin. The culture optical density (OD₆₀₀) was determined after overnight growth (∼20 h). The data are presented as the ratio of the OD₆₀₀ obtained in overnight cultures grown in THY containing the drug to that obtained in THY alone over the same time period. (B) Sensitivity of NZ131 and ZE491 to hydrogen peroxide. Bacteria were inoculated into fresh THY containing 1 mM hydrogen peroxide, and overnight growth was determined and presented as described for panel A. In both panel A and panel B, error bars represent the standard deviation of the mean (n = 3).