FIG. 3.

Iron uptake in P. aeruginosa wild-type and fpvA and tatABC mutants. P. aeruginosa PAO1 (▵), PAOΔtatABC (○), and PAOΔfpvA (⋄) cells at an OD₆₀₀ of 0.5 were incubated for 15 min in 50 mM Tris-HCl (pH 8.0) before transport assays were started by adding 100 nM Pvd-⁵⁵Fe. Aliquots (100 μl) of the suspension were removed at different times and filtered, and the retained radioactivity was counted. The experiment was repeated in the presence of 200 μM CCCP (▴, P. aeruginosa PAO1; •, PAOΔtatABC; and ⧫, PAOΔfpvA). The data presented in this figure are the results of three experiments (error bars are indicated). Similar results were obtained with P. aeruginosa PAK and PAKΔtatC.