Figure 3. Degradation of peroxides by the C. violaceum ATCC 12472 and ΔohrA and ΔohrR mutant strains.

Cultures grown in LB medium to an OD at 600 nm of 0.7 were divided and either treated with 300 µM tBOOH (A), 200 µM CuOOH (B) or 500 µM H₂O₂ (C). The level of residual peroxides remaining in the culture medium was determined at 5-min intervals using a xylenol orange assay.