Figure 8.

Copper sensitivity of Schu S4 and iron acquisition mutants. Bacteria resuspended in Chamberlin's defined medium (CDM) to an OD ₅₉₅ of 1 were spread on Mueller–Hinton agar (MHA)+. 10 μL of 10 mmol/L copper chloride was spotted on paper discs placed on the seeded plates and the effect on growth was evaluated after 48 h. The diameter of growth inhibition was measured and tabulated as mean ± standard error of the mean (SEM). The images document the phenotype and the gray coloration of the growth margins that was absent in the ΔfupA mutant.