FIG. 1.

Expression of ferric reductase in strains grown in LIM + 15 μM Cu(II) with no Fe (--) or with 15 μM Fe(III) (Fe). Ferric reductase was measured as the cell-mediated generation of the red Fe(II)-BPDS complex from Fe(III). Reductase was assayed every 2 h in exponential phase; each bar represents the peak of activity for each strain (mean ± standard deviation). The peaks occurred at the following time points in the absence and presence of Fe, respectively: WT, 12 and 0 h; frr1⁶⁰⁶ 12 and 2 h; frr2⁶⁰⁸, 6 and 6 h; frr3⁶³², 2 and 2 h; frr4⁶¹⁶, 12 and 2 h.