TABLE 6.
Expression of psyI-lacZ and psyR-lacZ in DC3000 and its RpoS−, PsyR−, and RpoS− PsyR− mutants
| Bacterial constructa | Relevant characteristic | β-Galactosidase activity (mean ± SD)b |
|---|---|---|
| DC3000(pMP220) | Wild type (vector) | 26 ± 4 |
| AC822(pMP220) | RpoS− PsyR+ (vector) | 29 ± 4 |
| AC823(pMP220) | RpoS+ PsyR− (vector) | 22 ± 3 |
| AC824(pMP220) | RpoS− PsyR− (vector) | 31 ± 6 |
| DC3000(pAKC1255) | Wild type (psyI-lacZ) | 1,131 ± 50 |
| AC822(pAKC1255) | RpoS− PsyR+ (psyI-lacZ) | 2,226 ± 106 |
| AC823(pAKC1255) | RpoS+ PsyR− (psyI-lacZ) | 149 ± 14 |
| AC824(pAKC1255) | RpoS− PsyR− (psyI-lacZ) | 162 ± 9 |
a
Cultures used for assays were grown to a Klett value of ca. 1,000 in KB medium plus tetracycline.
b
Expressed as Miller units.