FIG. 5.

Iron uptake by CFT073, CFT073cueO, and CFT073cueO(pCueO). Strains were incubated in the presence of 100 μM ⁵⁵Fe²⁺. The rate of ferrous iron uptake was determined by removing samples at 30, 60, 90, 120, 180, and 300 s and monitoring β emissions by using a Beckman LS3801 scintillation counter. ⁵⁵Fe²⁺ uptake rates were normalized to CFU/ml. Data are presented as the mean ⁵⁵Fe²⁺ uptake rates per CFU (±standard error) and represent the averages of the results for three independent experiments.