FIG. 2.

Rgg is involved in repression of H₂O₂ decomposition. Bacteria were harvested at e-stat or stat and, after being washed, were incubated in PBS in the presence of 40 μM of H₂O₂ for 1 h at 37°C. The incubations were cleared of bacteria by centrifugation, and the concentration of H₂O₂ in the supernatant was measured by a colorimetric method. The values represent mean percentages ± SD of decomposed H₂O₂ in five independent incubations. Control experiments included H₂O₂ decomposition in PBS containing 10,000 U/ml of beef liver catalase (PBS-CAT), in plain PBS, and in the presence of heat-killed (60 min; 90°C) bacteria (wt-K/Δrgg-K). Student's t test: ***, P < 0.005.