TABLE 1.

The effect of Cd(II) on colony-forming ability of Cd-1^a

Cd(II) concn (mM)	OD650 (after 28 h)	Initial CFU concn (per ml)a	Final CFU concn (per ml) (after 30 h)
0.2	0.082b	(1.2 ± 0.6) × 106c	(5.9 [0.7]) × 107d
0.5	0.062	1.2 × 106	(5.8 [1.2]) × 107d
1.0	0.090	1.2 × 106	9.6 × 107
2.0	0.084	1.2 × 106	8.0 × 107
5.0	0.012	1.2 × 106	2.0 × 106e
5.0	0.087	2.4 × 106f	3.6 × 107

^aExperiment was done under fermentative conditions. The inoculum was grown overnight at 30°C under aerobic conditions in the same minimal medium (described in the text). The minimal medium lacking a carbon source for growth was used for dilution purposes, while aerobic nutrient agar was used for CFU counts. 

^bInitial reading for all cultures was <0.008. 

^cAt this concentration, n was 4. An overnight culture was diluted 50 times. 

^dValues are averages of duplicate data, with ranges in parentheses. 

^eA count of 1.0 × 10⁷ CFU per ml was observed after 50 h. 

^f2× inoculum. Under similar conditions, cultures with 15 mM Cd(II) grew to an OD of ∼0.08 within 7 to 10 days and within 3 days when the inoculum was grown in nutrient broth.