FIG 6.

A. fumigatus secretes FC during growth on solid medium during both iron sufficiency and iron limitation. The Aspergillus fumigatus WT and ΔsidF mutant strains were point inoculated at a distance of 1.5 cm next to the bioassay strains ΔsidAΔftrA and ΔsidAΔftrAΔsit1Δsit2, using 10⁴ spores for all fungal strains. The growth conditions included iron limitation (−Fe), iron sufficiency (0.03 mM FeSO₄), and iron excess with a concentration of 5.0 mM FeSO₄. As a growth control, the bioassay strains were spotted next to ΔsidF on plates containing 0.1 μM TAFC or 0.1 μM FC. Plates were incubated at 37°C for 48 h.