Growth of hugZ mutants. Samples were tested in triplicate, and the data plotted are the means of three independent experiments together with the sample error. Symbols: A: H. pylori 26695 WT and ΔhugZ strains grown in BBF supplemented with 50 μM FeCl3 (iron-replete); B: WT andΔhugZ strains grown in BBF plus 75 μM desferal (iron-restricted) with or without 12.5 μM Hb supplement. The optical density of the bacteria was monitored at 600 nm. The key to symbols is shown in figure. Error bars indicate standard deviation from three replicate cultures. Hb, hemoglobin.