FIG. 8.

Absence of AnkB causes a decrease in KatB activity. Bacteria were grown aerobically overnight in L-broth medium at 37°C. Fresh prewarmed medium (1 volume of culture in 10-volume flasks) was inoculated with 1/100 the final culture volume, and the organisms were grown to an OD₆₀₀ of 0.6. Some bacteria (right panel) were then treated with a sublethal (0.35 mM) (11) dose of paraquat for 1 h, and the others (left panel) served as controls. Cell extracts were prepared, and 10 μg was subjected to nondenaturing polyacrylamide gel electrophoresis (5% polyacrylamide). The gels were then stained for catalase activity (58). Lanes: 1, PAO1; 2, ankB; 3, katA; 4, katB; 5, katA ankB.