FIG 2.

Dps mediates oxygen-induced resistance to tBOOH. (A) Oxidative stress mutants were tested for sensitivity to 55 mM tBOOH in disk diffusion assays. Dark gray bars represent assays exposed to air for 3 h prior to anaerobic incubation. Light gray bars represent assays that were maintained under anaerobic conditions. (B) Cell viability assays were performed using wild-type IB-101 and ΔoxyR and Δdps mutant strains. Cultures were grown to an OD of 0.3 and then split. Half of the culture was shaken in air for 3 h (solid lines), and the other half was incubated under anaerobic conditions (dashed lines). The cultures were then challenged with 500 μM tBOOH. Samples were taken over time, and the number of CFU per milliliter was determined. Data are means from three biological replicates performed over two independent experiments, with standard deviations.