TABLE 1.
Assessing transformation with plasmid pIL253/pNZ6202 by controlled expression of comX in L. lactis IL-9000, NZ9000, and pNZ9531-harboring KW2
| L. lactis strain | Plasmid content | Transformation rate (pIL253/pNZ6202)a with the following [nisin] (ng/ml): |
||
|---|---|---|---|---|
| 0 | 0.03 | 2 | ||
| IL-9000 | pNZ6200 | 1.5 × 10−7 ± 8.2 × 10−8 | 1.7 × 10−7 ± 1.5 × 10−7 | 3.4 × 10−7 ± 1.7 × 10−7 |
| pNZ8150 | ND | ND | ND | |
| KW2 | pNZ9531 + pNZ6200 | 1.5 × 10−6 ± 1.1 × 10−6 | 1.0 × 10−5 ± 9.2 × 10−7 | 5.2 × 10−6 ± 3.1 × 10−6 |
| pNZ9531 + pNZ6201 | 1.1 × 10−6 ± 1.1 × 10−6 | 6.2 × 10−6 ± 5.7 × 10−6 | 3.1 × 10−7 ± 2.2 × 10−7 | |
| pNZ9531 + pNZ8150 | ND | ND | ND | |
| NZ9000 | pNZ6200 | ND | ND | ND |
| pNZ8150 | ND | ND | ND | |
a
The transformation rate was calculated as number of pIL253 or pN6202 transformants/total number of cells/μg DNA. Values are means ± standard deviations. ND, not detected.