FIGURE 7.

Effects of iron on luxO transcriptional levels. Luciferase activity representing transcriptional levels of luxO was measured in wild type V. vulnificus, and Δfur. Cells were cultured with or without 200 μm iron chelator 2,2′-dipyridyl, which was supplemented when cells were at an A₆₀₀ of ∼0.2. Luminescence and cell density were measured at an A₆₀₀ ∼0.6. Relative light units (RLU) represent light units normalized to cell density (luminescence/A₆₀₀). Results are averages from three independent samples, and error bars denote standard deviations (**, p < 0.005; NS, not significant in Student's t test with p > 0.05).