FIG. 6.
A. Growth of the Δasb::kmr mutant in IDM with or without the addition of purified petrobactinBa. PetrobactinBa (2 μM) alleviated the growth defect of the Δasb::kmr mutant strain that was unable to produce this siderophore. B. Growth of the Δasb::kmr mutant in IDM supplemented with purified siderophores. PetrobactinBa, petrobactinMh, and aerobactin partially alleviated the Δasb::kmr growth defect. Salmochelin S4 failed to alleviate the Δasb::kmr growth defect. The indicated values are the averages of measurements of three independent growth curves, and each error bar corresponds to one standard deviation. All siderophore concentrations are 2 μM.