TABLE 2.
Determination of the number of spores of nonproteolytic C. botulinum that survived each heat treatment and resulted in growth at 30°C in the presence of lysozyme and of the log10 number of spores required for one spore to grow at 30°C in the presence and absence of lysozyme
| Heating temp (°C) | Heating time (min) | Log MPN, viable spores/tubea | Log 1/Pb
|
|
|---|---|---|---|---|
| With lysozyme | No lysozymec | |||
| Unheated | 0 | 5.79 | ||
| 70 | 104.9 | 5.57 | 0.21 | 1.17 |
| 529.1 | 5.07 | 0.71 | 1.04 | |
| 998.9 | 4.47 | 1.30 | 2.95 | |
| 1,596.3 | 4.21 | 1.56 | 2.62 | |
| 2,065.9 | 3.51 | 2.27 | 1.97 | |
| 2,544.5 | 4.26 | 1.51 | 2.36 | |
| 75 | 284.6 | 4.52 | 1.26 | 3.47 |
| 463.1 | 4.12 | 1.66 | 3.87 | |
| 1,071.5 | 3.65 | 2.12 | 4.52 | |
| 1,376.5 | 2.89 | 2.88 | >4.8 | |
| 1,793.0 | 3.65 | 2.12 | >4.8 | |
| 80 | 11.4 | 5.47 | 0.31 | 2.66 |
| 69.7 | 4.79 | 0.98 | >4.8 | |
| 98.0 | 4.98 | 0.80 | >4.8 | |
| 127.9 | 4.54 | 1.23 | >4.8 | |
| 183.8 | 3.97 | 1.81 | >4.8 | |
| 229.6 | 4.16 | 1.61 | >4.8 | |
| 294.9 | 4.15 | 1.62 | >4.8 | |
| 362.7 | 3.90 | 1.88 | >4.8 | |
| 85 | 23.3 | 4.45 | 1.32 | 4.00 |
| 35.7 | 4.68 | 1.09 | >4.8 | |
| 52.0 | 4.12 | 1.66 | >4.8 | |
| 57.8 | 4.20 | 1.58 | >4.8 | |
| 83.8 | 3.51 | 2.27 | >4.8 | |
| 90 | 10.3 | 4.04 | 1.74 | >4.8 |
| 10.9 | 3.11 | 2.67 | >4.8 | |
| 15.3 | 3.27 | 2.51 | >4.8 | |
| 23.5 | 3.43 | 2.34 | >4.8 | |
| 33.5 | 3.52 | 2.26 | >4.8 | |
a
The number of surviving spores was determined by estimation of MPN in PYGS medium containing lysozyme (480 U/ml) at 30°C.
b
Log10 number of spores required for one spore to grow and produce toxin at 30°C.
c
Value when recovery was at 30°C in the absence of lysozyme (data are from reference 10).