Effect of various salts added to LB medium on expression of SpoIISA toxin. Cells in all lanes were harvested from LB and DSM media, respectively after 5 h of growth. Lane 1 represents cells grown in LB medium; lane 2, LB medium supplemented with 0.1% KCl and 0.012% MgSO4; lane 3, LB medium supplemented with 1 mM Ca(NO3)2, 10 μM MnCl2 and 1 μM FeSO4; lane 4, LB medium supplemented with 0.1% KCl, 0.012% MgSO4, 1 mM Ca(NO3)2, 10 μM MnCl2 and 1 μM FeSO4; lane 5, LB medium supplemented with 10 μM MnCl2 and 1 mM Ca(NO3)2; lane 6, LB medium supplemented with 10 μM MnCl2; lane 7 represents cells grown in DSM medium. ΔIIS designates IB1235 strain (spoIIS null mutant) grown in LB medium and harvested after 5 h of growth. C-IISA designates a lane with 5 ng of purified cytosolic part of SpoIISA.