TABLE 4.
Efficiency of transformation of pNZ123 into electroporation-competent S. salivarius ATCC 25975 and other strainsa
| S. salivarius strain | Transformation efficiency (transformants/μg of pNZ123) |
|---|---|
| ATCC 25975 | 2.2 × 105 ± 1.3 × 105b |
| ATCC 25975c | 8.4 × 104 ± 3.7 × 104 |
| ATCC 7073 | 9.3 × 105 ± 5.0 × 105 |
| ATCC 13419 | 5.3 × 104 ± 1.6 × 104 |
| 30.1 | 5.3 × 102 ± 3.8 × 101 |
a
All cells were transformed with 1 μg of pNZ123 DNA.
b
Average ± standard deviation for three to six samples of each S. salivarius preparation.
c
This preparation had been stored at −80°C for 20 months at the time of testing.