FIGURE 1.

Growth of mutants harboring feoA or feoB suppressor alleles or deletions in the wild type background. Cells of mutant strains harboring feoB(Y454term), feoA(E40K) ΔfeoA, and ΔfeoB grown in liquid cultures supplemented with 100 nm heme were serial diluted 10⁻¹–10⁻⁵-fold, and 10 μl was spotted on plates containing either 1.65 mm FeSO₄ (A) or 50 μm FeSO₄ (B). Each panel represents a single plate, and the image was separated for clarity of presentation.