Fig. 4.

Kinetics of ⁵⁵Fe-anguibactin uptake by V. anguillarum. Characterization of FatC (A), FatD (B) and FatB (C). Vibrio anguillarum strains grown to exponential phase (OD₆₀₀ = 0.3–0.6) in CM9 were washed twice and resuspended in casamino acid-free CM9 containing the chelator sodium nitrilotriacetate at a concentration of 100 μM. The anguibactin siderophore was loaded with ⁵⁵Fe by incubation with ⁵⁵FeCl₃(1 μCi ml⁻1) for 6 h and then mixing it with an equal volume of V. anguillarum in CM9 salts. At each time point 1 ml of mixture was withdrawn, filtered through a 0.45 μm filter (Millipore Corporation) and immediately washed twice with10 ml of 100 mM Sodium citrate. The filters were air-dried and the radioactivity was measured in a liquid scintillation counter. The values were normalized to an OD (OD₆₀₀ = 1), and results were fitted using the GraphPad Prism4 program.