TABLE 3.
Expression of the pelX::uidA fusion in various mutants
| Strain (main genotype) | Carbon source | Inducera | Sp actb of:
|
|
|---|---|---|---|---|
| β-Glucuronidase | Pectate lyase | |||
| A2524 (pelX::uidA) | Glycerol | None | 62 | 0.06 |
| Glycerol | Polygalacturonate | 232 | 2.27 | |
| Glucose | None | 16 | 0.04 | |
| Glucose | Polygalacturonate | 209 | 1.78 | |
| A2737 (kdgR pelX::uidA) | Glycerol | None | 2,055 | 1.11 |
| Glycerol | Polygalacturonate | 1,551 | 4.32 | |
| A2740 (kdgK pelX::uidA) | Glycerol | None | 66 | 0.06 |
| Glycerol | Polygalacturonate | 642 | 18.23 | |
| A2738 (pecS pelX::uidA) | Glycerol | None | 54 | 0.36 |
| Glycerol | Polygalacturonate | 225 | 3.49 | |
| A2739 (pecT pelX::uidA) | Glycerol | None | 49 | 0.45 |
| Glycerol | Polygalacturonate | 186 | 3.66 | |
| A2762 (crp pelX::uidA) | Glucose | None | 4 | 0.01 |
| Glucose | Polygalacturonate | 3 | 0.16 | |
Cultures were grown at 30°C in M63 glycerol minimal medium in the presence or absence of polygalacturonate (0.25%) to late log phase.
β-Glucuronidase specific activity reflects the expression of the pelX::uidA fusion and is expressed as nanomoles of product liberated per minute per milligram of bacterial dry weight. Pectate lyase specific activity corresponds to the action of the endo-Pels and is expressed as micromoles of product liberated per minute per milligram of bacterial dry weight. The results reported are the mean of at least three independent experiments with standard deviations corresponding to less than 20%, except for the very low activities in the crp mutant, for which standard deviations reached about 30%.