FIG. 5.

β-Galactosidase activities of xcinA promoter-lacZ fusions. E. coli strains were grown to log phase in LB medium and resuspended in M9 medium under specific nutrient conditions for induction. (A) Cells grown in M9 medium. Bar 1, no mitomycin C; bar 2, induction with 0.3 μg/ml mitomycin C. (B) Activities at different temperatures. Bar 1, 30°C; bar 2, 37°C; bar 3, 42°C. (C) Cells grown in M9 media. Bar 1, M9 medium control; bar 2, M9 medium with 2 μg/ml FeSO₄; bar 3, M9 medium with 2 μg/ml FeSO₄ and 25 mM Desferal. (D) Effect of glucose. Bars 1 and 2, no glucose at 0 and 2 h, respectively; bars 3 and 4, cells with 0.2% glucose at 0 and 2 h, respectively. The data are expressed in Miller units.