FIG. 2.

Catalase activities of N. gonorrhoeae 1291 (wild type) and oxyR::kan mutant during growth overnight (A) and H₂O₂ treatment (B). In these assays, cells were grown on BHI agar containing 10% levinthal (2) and 1% supplex (Biomerieux) (white columns) or BHI agar containing levinthal, supplex, and 100 μM MnSO₄ (shaded columns). Experiments were performed in triplicate. The y-axis error bars each represent ±1 standard deviation of the mean. Student's t test was performed to determine the statistical significance between different samples. The unit of catalase is reported the concentration of H₂O₂ decomposed per minute per milligram of total protein. In the wild type, Mn increased the catalase activities slightly (P = 0.04135 [a]). Mn supplementation also increased the catalase activities slightly in the oxyR::kan mutant (P = 0.06356 [b]). H₂O₂ did not induce the catalase activity significantly in the oxyR::kan mutant (P = 0.6417 [c]).