TABLE 2.
Effect of different divalent metals on the growth and glucose incorporation in D. radioduransa
| Metal (100 μM) | Cell density (108/ml) at stationary phase (%) | % Of glucose incorporated into 108 cells |
|---|---|---|
| Control | 2.70 ± 0.05 (100) | 4.4 |
| Mn | 3.55 ± 0.03 (132)b | 4.1 |
| Zn | 1.48 ± 0.29 (55)c | 2.8d |
| Mg | 2.52 ± 0.30 (93) | 3.9 |
| Ca | 3.11 ± 0.06 (115) | 4.4 |
| Ba | 2.79 ± 0.03 (103) | 2.8d |
| Cu | 1.24 ± 0.03 (46)c | 2.2d |
| Ni | 1.90 ± 0.02 (70) | 3.2 |
| Co | 0.32 ± 0.01 (12)c | 0.9d |
| Fe | 2.48 ± 0.12 (91) | 3.5 |
a
Cells were grown on 1 ml of half-strength TY medium enriched with 5 mM d-glucose-UL-14C plus the chloride salt of the test metal. Triplicate cultures were grown for 40 h and were washed and courted. Results were analyzed by one-way analysis of variance and were expressed as the means ± standard deviations. The significance level was set at 95%. About 43% of the glucose was incorporated into the biomass of E. coli grown on the control medium.
b
Mn significantly stimulated the cell growth.
c
Zn, Cu, and Co inhibited cell growth significantly.
d
Zn, Ba, Cu, and Co significantly inhibited the incorporation of glucose into the biomass.