Fig. 7. Magnesium supplementation rescues the ΔybeX phenotypes in various growth media. (A ) The WT and ΔybeX cells were grown overnight in LB, SOB growth media, or LB supplemented with 10 mM MgCl2. The cells were serially diluted and spotted on LB agar plates. The plates with antibiotics were incubated at 37°C. There were also controls without antibiotics, denoted “No AB”, at 37°C or 42°C, as indicated in the first two sub-panels. (B ) A single colony of WT or ΔybeX was grown overnight in the magnesium-limited peptide-based medium (PBM). 0 µM denotes no MgCl2 supplementation; otherwise, PBM is supplemented with 50, 100 and 200 µM MgCl2. The cells were plated as in panel A. (C ) WT and ΔybeX cells were grown overnight at 37°C in MOPS minimal medium supplemented with indicated concentrations of MgCl2 and 0.5% glucose. The outgrowth from these stationary phase cultures was tested in 1xMOPS minimal medium (0.5% glucose, 525 µM MgCl2) in 96-well plates at 37°C with aeration. The growth curves summarize three independent experiments shown as fitted logistic curves. Shaded areas represent the 95% CI-s.