TABLE 3.
Repression of malK when the glycerol regulon is controlled by an IPTG-inducible tac promoter
| Carbon source | β-Galactosidase activitya with introduced plasmid
|
Repression by glpb | |
|---|---|---|---|
| pACT3 | pGPH11542 (glpFKX) | ||
| Glycerol | 120 ± 13 | 24 ± 7 | 5 |
| Maltose | 2,870 ± 31 | 1,177 ± 231 | 2.4 |
| G3P | 92 ± 33 | 18 ± 7 | 5.1 |
| Ribose | 661 ± 47 | 36 ± 3 | 18.4 |
| Succinate | 177 ± 54 | 30 ± 7 | 5.9 |
| Mannose | 237 ± 18 | 112 ± 6 | 2.1 |
| Glucose | 27 ± 7 | 55 ± 10 | 0.5 |
a
β-Galactosidase activity of a strain with Φ(malK′-lacZ+)1 in a GPH11296 background was assayed during growth at 30°C in MM adjusted to pH 7 and supplemented with the indicated carbon source (0.4%) and chloramphenicol. IPTG (5 or 10 μg/ml) was added to the medium.
b
Repression values correspond to the ratio between β-galactosidase activities of the strain with pACT3 and the strain with pGPH11542.