TABLE 1.
Effect of the assay temperature on nisin-induced CF efflux from liposomes derived from L. monocytogenes Scott A grown under various conditionsa
| Cell growth conditionsb | CF effluxc at given temp
|
|||||
|---|---|---|---|---|---|---|
| Initial efflux rate (%/min)
|
Overall efflux (%)
|
Time to plateau (s)
|
||||
| 4°C | 22°C | 4°C | 22°C | 4°C | 22°C | |
| 30°C, air | −0.1 | 5.5 | −0.3 | 30.9 | >1,200 | 600 |
| 4°C, air | 0.3 | 20.5 | 5.1 | 82.6 | >1,200 | 380 |
| 4°C, CO2 | 2.1 | 24.8 | 18.1 | 92.5 | >1,200 | 300 |
a
Nisin concentration was 2.5 μg/ml. Values represent the averages from two independent experiments.
b
Cells were grown in B-BHI broth in the absence of nisin under conditions indicated.
c
The initial efflux rate of CF was calculated from the slope of a tangent to the efflux curve at 200 s after addition of nisin. Overall percentage of CF efflux was calculated at 600 s. Time for plateau of CF leakage was calculated after addition of nisin (seconds). The lipid concentration for cells preadapted to 30°C in air, 4°C in air, and 4°C in 100% CO2 was 2.5, 2.45, and 3.0 μM, respectively.