FIG. 1.

Anion-exchange HPLC analysis of L. pneumophila CDM culture supernatants. Concentrated supernatants obtained from deferrated CDM cultures of wild-type strain 130b were injected onto a TSK-GEL DEAE-2SW anion-exchange column and then subjected to NaCl elution over a 120-min period. Fractions obtained were analyzed at A₂₂₀ and tested for their reactivity (positive [+] or negative [−]) in the CAS assay and the feoB bioassay. Images showing the ability or inability of a supernatant fraction to stimulate the growth of the feoB mutant on low-iron BCYE plates are inserted over the A₂₂₀ scan. The results presented are representative of at least four independent experiments. AU, arbitrary units.