Fig 2.

Accumulation of Fe and Mn in pneumococcal cells grown in different growth media. (A) Internal Fe/Mn ratio of D39 WT, isogenic deletion mutant (ΔritR), and complemented (ΔritR::ritR) strains when grown in Fe-CDM compared to Mn-CDM. (B) Internal Fe/Mn ratio of the D39 ΔritR strain when grown in Mn-CDM and Fe-CDM supplemented with 0.1, 1, 10, and 100 μM Mn. The results are shown as averages of three independent experiments, and the results were normalized with the cellular protein concentration. Samples were collected during the exponential phase of growth, with the exception of the ΔritR strain when grown in Fe-CDM (the sample was collected during the lag phase of growth). The error bars indicate the standard deviations of three independent experiments.