Fig. 1.

Pyoverdine concentrations in P. aeruginosa culture supernatants. (A) Wild-type (WT), ΔpvdS mutant, ΔlipA ΔlipC double mutant, and the double mutant with a lipA or lipC expression plasmid, which also harbored the gene for the lipase-specific chaperone lipH for proper folding of the lipases, were grown for 8 h at 37°C in M9 minimal medium without iron supplementation, and pyoverdine concentrations were determined in cell-free supernatants (9). (B) The wild type and a ΔlipA mutant harboring the empty vector (ev) or a lipA expression plasmid were grown in rich LB or minimal M9 medium, and the relative pyoverdine concentrations were determined after 8 h of growth.