FIG 2.

Differential growth of single-system strains on solid or in liquid medium. (A) For colony size assays (left), the diameters of 10 well-isolated colonies were measured using a reticle after 24 h of incubation at 37°C on unsupplemented LB agar or agar supplemented with FeSO₄ or heme. The data indicate the means and standard deviations and are representative of biological replicates. For monitoring growth in liquid medium (right), overnight cultures of strains were diluted 1:100 into LB with supplements as indicated. The values are the means and standard deviations of optical density values (A₆₅₀) measured after 10 h of growth for three independent experiments. The strains assessed in each panel are O395 (wild type), EPV102 (null), EPV104 (vFeo), EPV115 (vFbp), EPV103 (vVct), and EPV126 (vVib). In both assays, *, **, and *** indicate significance as determined by two-way analysis of variance, Holm-Šidák multiple-comparison test, with P values of <0.05, 0.01, and 0.0001, respectively. (B and C) The growth of the individual strains was assayed through the measurement of A₆₅₀ over time in LB medium (B) and LB medium with heme supplementation (C). The means from three independent experiments are represented in both assays.