TABLE 3.
β-Galactosidase activity of zntA- and cadA-lacZ fusionsa
| Fusion and strain or mutation | β-Galactosidase activity (U/mg [dry mass]) in TMM with: |
||
|---|---|---|---|
| No addition | 200 μM Zn(II) | 50 μM Cd(II) | |
| Φ(cadA-lacZ) | |||
| AE104 | 1.23 ± 1.33 (1.00) | 24.3 ± 5.9 (19.8) | 259.8 ± 31.4 (211) |
| ΔcadR | 211.0 ± 37.4 (172) | 225.8 ± 48.7 (184) | 231.1 ± 23.7 (188) |
| ΔcadR vc | 193.5 ± 42.9 (157) | 245.3 ± 78.4 (199) | 200.8 ± 27.9 (163) |
| ΔcadR +cadR | 226.0 ± 50.5 (184) | 199.4 ± 53.7 (162) | 210.7 ± 29.5 (171) |
| ΔcadR +zntR | 227.7 ± 50.5 (185) | 180.7 ± 47.0 (147) | 201.3 ± 38.4 (164) |
| ΔzntR | 11.0 ± 4.5 (8.90) | 149.5 ± 21.4 (122) | 249.7 ± 70.2 (203) |
| ΔzntR vc | 9.8 ± 6.2 (7.97) | 79.1 ± 34.5 (64.3) | 235.0 ± 28.5 (191) |
| ΔzntR +zntR | 9.9 ± 8.2 (8.05) | 70.6 ± 33.0 (57.4) | 234.0 ± 47.7 (190) |
| ΔzntR +cadR | 6.4 ± 3.8 (5.20) | 107.9 ± 34.8 (87.9) | 240.1 ± 30.8 (195) |
| Φ(zntA-lacZ) | |||
| AE104 | 23.0 ± 8.4 (1.00) | 182.5 ± 44.1 (7.93) | 211.1 ± 16.6 (9.18) |
| ΔzntR | 0.1 ± 0.00 (0.01) | 0.5 ± 1.10 (0.02) | 8.5 ± 4.20 (0.37) |
| ΔzntR vc | 0.1 ± 0.00 (0.01) | 0.1 ± 0.00 (0.01) | 6.0 ± 4.80 (0.26) |
| ΔzntR +zntR | 14.2 ± 11.5 (0.62) | 57.8 ± 17.4 (2.51) | 51.5 ± 17.9 (2.24) |
| ΔzntR +cadR | 0.1 ± 0.10 (0.01) | 0.1 ± 0.10 (0.01) | 10.2 ± 5.50 (0.44) |
| ΔcadR | 2.2 ± 4.0 (0.10) | 170.8 ± 60.0 (7.43) | 171.5 ± 33.8 (7.46) |
| ΔcadR vc | 0.2 ± 0.1 (0.01) | 103.0 ± 45.1 (4.48) | 105.5 ± 43.9 (4.59) |
| ΔcadR +zntR | 0.2±.0.1 (0.01) | 93.5 ± 34.1 (4.07) | 143.2 ± 60.7 (6.23) |
| ΔcadR +cadR | 0.2 ± 0.1 (0.01) | 81.0 ± 16.9 (3.52) | 164.1 ± 56.5 (7.13) |
β-Galactosidase activity was determined by the 96-well plate method of the strains containing a cadA-lacZ or a zntA-lacZ fusion. vc, strain complemented in trans with a vector control; +zntR or +cadR, the same vector containing zntR (Rmet_3456) or cadR (Rmet_2302), respectively. Values are means and deviations from ≥3 experiments. Values in parentheses are the ratios of the respective value compared to parent strain AE104 without additions. Growth in the presence of 100 μM Co(II) had an effect only once, a 2.81-fold up-regulation from 0.05 ± 0.02 to 0.14 ± 0.02 U/mg in the ΔzntR strain. All other cobalt data did not yield any indication of a cobalt-dependent regulation and are not shown.