TABLE 2.

Effect of varying the external cation type and concentration on the intracellular cation concentration^a

Growth conditions	Ion	Concn (ppm)	Cell vol (liter)	Concn (mM)
LB	Na+	0.65	1 × 10−15	10
	K+	42.76	1 × 10−15	404
	Li+	5.9 × 10−4	1 × 10−15	0.02
	Mg2+	34.93	1 × 10−15	290
LB + 200 mM LiCl	Na+	0.66	8.5 × 10−16	12
	K+	34.8	8.5 × 10−16	387
	Li+	0.028	8.5 × 10−16	1.4
	Mg2+	21.9	8.5 × 10−16	316
LB + 60 mM MgCl2	Na+	1.3	7.4 × 10−16	14
	K+	40.2	7.4 × 10−16	434
	Li+	3.46 × 10−4	7.4 × 10−16	0.012
	Mg2+	34.17	7.4 × 10−16	330
LB + 200 mM NaCl and 60 mM MgCl2	Na+	0.77	1 × 10−15	11
	K+	43.3	1 × 10−15	405
	Li+	8.7 × 10−4	1 × 10−15	0.03
	Mg2+	29.23	1 × 10−15	338

^aCells were grown and processed by ICP-MS analysis as described in Materials and Methods.