FIG. 1.

Effect of iron levels and fur deletion on the expression of fes-fepA-fluc. (A) Regulation of fes-fepA-fluc by iron. The medium contained 15 μM of iron (final concentration); the iron availability concentration was adjusted by adding different concentrations of 2,2′-dipyridyl as indicated. (B) Comparison of fes-fepA-fluc expression in the wild type (strain SCH35) and fur deletion mutant (strain SCH113). The iron level was adjusted by adding 2,2′-dipyridyl (200 μM) or iron at various concentrations as indicated. The solid bar represents the wild type (strain SCH35), and the striped bar represents the fur deletion mutant (strain SCH113). Values are means of data from triplicate cultures (with standard deviation).