Fig. 1.
Induction of L. monocytogenes FrvA imposes iron deprivation and inhibits cell growth of B. subtilis. (A) Levels of intracellular metals (Fe, Mn, and Co) were monitored for 3 h after 1 mM IPTG addition by inductively coupled plasma mass spectrometry (ICP-MS). The total concentration of ions was expressed as µg ion per gram of protein (mean ± SD; n = 3). Significant differences between WT and induced Pspac-frvA cells are determined by two-tailed t test as indicated: *P < 0.01. (B) Representative growth curves of the same strains as A in LB medium amended with 10 µM FeSO4. For IPTG-treated cells, 1 mM IPTG was added to cell culture when OD600 reaches ∼0.25. Experiments were performed at least three times with three biological replicates.