TABLE 5.
Inducibility of promoters regulating the transcription of transporter genes of P. putida KT2440 in HMM and LB media at different stages of growth
| Medium, promoter, and phase | Background luminescence (RLU)a | Maximal induction coefficient (fold) withb:
|
|||||
|---|---|---|---|---|---|---|---|
| Zn2+ | Cd2+ | Pb2+ | Co2+ | Ni2+ | Hg2+ | ||
| HMM medium | |||||||
| PcadA1 | |||||||
| Lag phase | 30 | 4.0 ± 1.3 | |||||
| Early exponential phase | 45 | 22 ± 13 | |||||
| Exponential phase | 30 | 26 ± 5 | 2.2 ± 0.2 | ||||
| Late exponential phase | 30 | 27 ± 6 | |||||
| Stationary phase | 25 | 11 ± 2 | |||||
| PcadA2 | |||||||
| Lag phase | 9,000 | 3.7 ± 0.1 | 6.6 ± 2.5 | ||||
| Early exponential phase | 20,000 | 13 ± 7 | 5.1 ± 1.7 | 3.1 ± 1.0 | |||
| Exponential phase | 35,000 | 9.4 ± 0.1 | 6.1 ± 1.0 | 5.1 ± 0.1 | 2.7 ± 0.6 | ||
| Late exponential phase | 40,000 | 2.2 ± 0.1 | 6.8 ± 1.4 | 3.5 ± 0.8 | 2.2 ± 0.7 | ||
| Stationary phase | 50,000 | 2.1 ± 0.1 | 5.1 ± 1.2 | 2.1 ± 0.6 | 3.0 ± 0.3 | 2.5 ± 0.5 | |
| Pczc1 | |||||||
| Lag phase | 200 | 69 ± 24 | 16 ± 7 | 8.0 ± 2.3 | 5.4 ± 1.4 | 13 ± 8 | |
| Early exponential phase | 400 | 280 ± 60 | 52 ± 8 | 15 ± 5 | 13 ± 2 | 40 ± 15 | 3.4 ± 0.2 |
| Exponential phase | 250 | 590 ± 70 | 120 ± 20 | 7.8 ± 5.6 | 220 ± 80 | ||
| Late exponential phase | 200 | 1100 ± 200 | 23 ± 10 | 4.7 ± 0.1 | |||
| Stationary phase | 200 | 950 ± 220 | 2.4 ± 0.5 | 2.6 ± 1.4 | |||
| LB medium | |||||||
| PcadA1 | |||||||
| Lag phase | 50 | 35 ± 16 | |||||
| Early exponential phase | 250 | 78 ± 20 | 5.5 ± 2.2 | ||||
| Exponential phase | 400 | 78 ± 23 | |||||
| Stationary phase | 400 | 77 ± 30 | |||||
| PcadA2 | |||||||
| Lag phase | 8,000 | 2.3 ± 0.1 | 3.3 ± 0.5 | 3.7 ± 0.3 | 2.0 ± 0.3 | 2.9 ± 1.3 | 2.3 ± 0.1 |
| Early exponential phase | 85,000 | 3.9 ± 0.5 | 3.3 ± 0.3 | 2.6 ± 0.7 | 5.6 ± 1.4 | ||
| Exponential phase | 400,000 | 2.0 ± 0.4 | 3.1 ± 0.2 | 3.2 ± 0.3 | 2.5 ± 0.1 | ||
| Stationary phase | 350,000 | 2.6 ± 0.1 | 3.9 ± 0.2 | 3.8 ± 0.9 | 2.1 ± 0.2 | ||
| Pczc1 | |||||||
| Lag phase | 300 | 120 ± 10 | 30 ± 8 | 7.5 ± 0.7 | 3.2 ± 0.1 | ||
| Early exponential phase | 3,000 | 130 ± 30 | 43 ± 1 | 14 ± 3 | 6.4 ± 0.4 | 30 ± 6 | 17 ± 3 |
| Exponential phase | 4,000 | 450 ± 110 | 18 ± 12 | 3.1 ± 0.4 | 4.6 ± 1.7 | 3.4 ± 1.5 | 2.7 ± 0.1 |
| Stationary phase | 1,500 | 510 ± 180 | |||||
a
Bacterial luminescence in a metal-free environment (water), representing the noninduced level of expression from the promoter. RLU, relative light units.
b
The data indicate by how much the bacterial luminescence in metal solutions exceeded the background luminescence. The maximal induction coefficient is shown, and in different cases it was measured with different metal concentrations; only induction coefficients greater than 2 are shown. The data are the means ± standard deviations of three independent experiments.