TABLE 2.
Percentage of dead cells in cultures of C. metallidurans mutant cellsa
| Bacterial strain |
% dead cells |
|||
|---|---|---|---|---|
| Glutathione | Present (GSH+) |
Absent (ΔgshA) |
||
| Added Cu(II) | No | At IC50 | No | At IC50 |
| Δcus | 2.81 ± 2.72 | 15.9 ± 16.7 | 1.32 ± 0.58 | 7.04 ± 4.36 |
| AE104 | 4.93 ± 2.40 | 9.12 ± 5.98 | 2.81 ± 1.76 | 5.54 ± 3.23 |
| Δcus Δgig | 3.41 ± 3.88 | 18.2 ± 26.4 | 2.24 ± 0.44 | 3.64 ± 2.07 |
| Δgig | 3.45 ± 0.71 | 5.73 ± 2.68 | 2.54 ± 1.91 | 4.10 ± 2.38 |
| Δcop Δgig | 2.51 ± 2.30 | 10.1 ± 10.1 | 4.50 ± 0.39 | 30.7 ± 10.0 |
| Δcop | 2.90 ± 1.58 | 9.67 ± 5.66 | 2.74 ± 3.04 | 4.69 ± 3.28 |
| Δcop Δcus | 3.57 ± 2.11 | 27.3 ± 17.1 | 2.75 ± 1.89 | 13.7 ± 5.6 |
| Δcop Δcus Δgig | 5.51 ± 3.13 | 17.1 ± 6.1 | 6.54 ± 4.06 | 26.1 ± 12.6 |
| Δcup | 2.43 ± 2.85 | 8.61 ± 6.25 | 1.24 ± 0.62 | 4.91 ± 2.79 |
| Δcup Δgig | 4.53 ± 2.20 | 4.66 ± 4.53 | 4.35 ± 1.41 | 10.6 ± 1.9 |
| Δcup Δcus | 4.35 ± 3.16 | 2.58 ± 2.65 | 4.19 ± 2.23 | 20.0 ± 13.5 |
| Δcop Δcup | 3.96 ± 2.04 | 10.5 ± 4.9 | 9.47 ± 5.69 | 9.37 ± 3.62 |
| Δcup Δcus Δgig | 5.12 ± 2.44 | 3.78 ± 2.42 | 3.95 ± 3.57 | 2.76 ± 2.84 |
| Δcop Δcup Δcus | 4.47 ± 1.42 | 6.18 ± 8.05 | 4.12 ± 2.43 | 7.34 ± 3.73 |
| Δcop Δcup Δcus Δgig | 3.86 ± 3.22 | 9.04 ± 9.46 | 5.92 ± 2.86 | 10.0 ± 2.00 |
| Δcop Δcup Δgig | 2.55 ± 0.99 | 4.85 ± 6.21 | 1.38 ± 0.64 | 7.82 ± 3.97 |
The indicated mutant strains of C. metallidurans AE104 and the ΔgshA mutant were incubated for 20 h in the presence of Cu(II) provided at the IC50 concentration (Table 1) of the respective strain, without copper (negative control) and a Live/Dead staining was applied. The percentage of the dead cells (filter 3, λEx 546 nm/λEm 590 nm) of the total cells (filter 2, λEx 450 to 490 nm/λEm 520 nm) is given. Bold-faced values are Q > 1.5 and D > 1, n = 4 without copper and n = 6 with copper. Bold-faced and italic values have higher min, median and max values of these 4 or 6 experiments in the presence of copper compared to without copper but the mean values could not be judged as different due to a large deviation. Underlined values indicate a >50% increase in the presence of copper at the IC50 concentration but not judged as different due to large deviations. Light gray fields indicates no increased copper-mediated killing in the presence of GSH. Midgray field indicates neither in the presence nor the absence of GSH.