FIGURE 2.

Initial characterization of the pyoverdine PVD_A506. A and B, fluorescence in the range of 350–800 nm of PVD_A506 in culture supernatant from P. fluorescens A506, excited at 200–340 nm in the absence (A) or presence (B) of 1 mm FeCl₃. AU, arbitrary units. C, electronic absorption spectra of the samples from A and B. D, electronic absorption spectrum of the Csáky assay (16), indicating the presence of hydroxamates. Fresh medium (CAA) was treated in the same manner as the culture supernatant (PVD_A506).