Table 1 Characteristics of Escherichia coli MC1061-based luminescent heavy metal sensors and toxicity control strains
| Â | Sensor strains | Control strains | |||
|---|---|---|---|---|---|
| Â | MC1061 (pmerRBSBPmerlux) | MC1061 (pSLzntR/ pDNPzntAlux) | MC1061 (pSLcueR/ pDNPcopAlux) | MC1061 (pSLlux)a | MC1061 (pDNlux)b |
Background luminescence c | 230 ± 90 | 2940 ± 930 | 520 ± 70 | 575000 ± 35200 | 6500 ± 2270 |
Maximum induction d | 400 | 20 | 100 | no induction | no induction |
No of cells in the test (100 μl) | 4 × 107 | 107 | 8 × 106 | 8 × 106 | 107 |
Compound | Limit of determinatione/Toxicityf, M (mg of compound l-1) | Toxicity (2-h EC50g), M (mg of compound l-1) | Â | ||
HgCl 2 | 10-10 (0.00003)/5 × 10-6 (1.4) | 8 × 10-8 (0.02)/10-5 (2.7) | no induction | 10-6 (0.4) | 10-6 (0.4) |
CH 3 HgCl | 8 × 10-12 (0.000002)/5 × 10-8 (0.01) | not tested | not tested | 3 × 10-6 (0.7) | not tested |
CdCl 2 | 3 × 10-7 (0.06)/5 × 10-4 (92) | 10-8 (0.003)/5 × 10-6 (0.9) | no induction | 4 × 10-4 (70) | 2 × 10-4 (31) |
ZnSO 4 h | no induction | 5 × 10-6 (0.8)/5 × 10-2 (8000) | no induction | 10-2 (1600) | 4 × 10-3 (640) |
Pb(NO 3 ) 2 | no induction | 7 × 10-7 (0.2)/10-3 (330) | no induction | 2.4 × 10-4 (79) | 6 × 10-4 (190) |
CuSO 4 i | not tested | not tested | 10-7 (0.02)/10-3 (240) | not tested | 5.4 × 10-4 (86) |
AgNO 3 | not tested | not tested | 2 × 10-6 (0.3)/10-5 (2.6) | not tested | 2 × 10-6 (0.3) |