FIG 2.

LB contains H₂O₂. (A) Effects of catalase (2,000 U) on the plating defect of indicated strains on LB plates. Experiments were performed at least three times, and similar results were obtained each time. (B) H₂O₂ assay. H₂O₂ concentrations in indicated media (No cell) and in cultures at the indicated cell densities (OD₆₀₀ of 0.3 and 1.2) were determined. The data reported represent the mean results ± standard deviations (SD) (n = 4).