TABLE 3.
β-galactosidase activities produced by various Lac− strains
| Strain | Properties | Plasmid | β-galactosi- dase activity (Miller units) | Fold increase due to plasmid |
|---|---|---|---|---|
| FC40 | Wild type | None | 2.3 | |
| CRS247 | Wild type | pCRS3 (vector) | 3.7 | 1.6 |
| CRS248 | Wild type | pCRS4 (gene II) | 3.0 | 1.3 |
| CRS241 | Wild type + nick site | None | 2.0 | |
| CRS243 | Wild type + nick site | pCRS3 (vector) | 2.7 | 1.4 |
| CRS244 | Wild type + nick site | pCRS4 (gene II) | 2.4 | 1.2 |
| J65 | traD | None | 1.4 | |
| CRS251 | traD | pCRS3 (vector) | 2.9 | 2.1 |
| CRS252 | traD | pCRS4 (gene II) | 2.1 | 1.6 |
| CRS242 | traD + nick site | None | 1.5 | |
| CRS245 | traD + nick site | pCRS3 (vector) | 2.8 | 1.9 |
| CRS246 | traD + nick site | pCRS4 (gene II) | 2.3 | 1.5 |