TABLE 1.
pHi values of L. monocytogenes cells exposed to various concentrations of nisin in a broth system compared to cells immobilized on a filter membranea
| Nisin concn (IU/ml) | pHi
|
|
|---|---|---|
| In a broth system | On a filter membrane | |
| Control | 7.8 (0.5) | 7.8 (0.1) |
| 5 × 10−4 | 7.9 (0.2) | NTb |
| 5 × 10−3 | 7.9 (0.1) | NT |
| 5 × 10−2 | 6.5 (1.2) | NT |
| 5 × 10−1 | 5.7 (0.4) | NT |
| 5 × 100 | 5.5 (0.1) | NT |
| 5 × 102 | 5.5 (0.1) | NT |
| 5 × 103 | NT | 7.9 (0.1) |
| 5 × 104 | 5.6 (0.2) | 5.5 (0.0) |
a
The exposure time was 12 min. The values are averages (standard deviations) based on the results obtained for 30 single cells.
b
NT, not tested.