Fig 3.

Effect of bacterial HGA-melanin on iron uptake by L. pneumophila 130b. Wild-type strain 130b (A), feoB mutant strain NU269 (B), and lly mutant strain NU408 (C) that had been grown in deferrated CDM and then resuspended in buffer were mixed with ⁵⁵FeCl₃ in the presence of PBS (white bars), acid-precipitated HGA-melanin obtained from 130b culture supernatants (black bars), or acid-precipitated material from lly mutant strain NU408 culture supernatants (bars with horizontal lines), and after 0, 60, and 120 min of incubation, the levels of intracellular radiolabeled iron were determined. The data are the means and standard deviations obtained from triplicate samples. In panels A and C, 130b melanin resulted in greater levels of uptake relative to those for the mutant sample and the PBS control (***, P < 0.001).