TABLE 1.

Initial rates of cadmium uptake by E. coli and L. plantarum in APT medium^a

Cd2+ (μM)	Cd2+ uptake (nmol g of dry cell−1 min−1) by:
	L. plantarum ATCC 14917		E. coli XL1-blue
	Mn2+ starved	Mn2+ sufficient
0.02	73 ± 6	0.5 ± 0.1	0.3 ± 0.1
0.2	802 ± 42	6.1 ± 0.3	1.8 ± 0.2
2	2,821 ± 112	52 ± 3	5.8 ± 0.52
20	3,563 ± 308	258 ± 16	23 ± 1
100	3,214 ± 382	ND	41 ± 10
200	3,082 ± 203	520 ± 42	45 ± 7

^aCells were prepared and preincubated for 10 min at 37°C in low-Mn²⁺ APT medium containing different amounts of Cd²⁺ as described in the text. Initial uptake values were determined with 0.2-ml samples filtered 15 s after radioactive Cd²⁺ was added. Values are means ± ranges from replicate experiments. ND, not determined.