TABLE 1.
Comparison of D values for cold-shocked spores of B. subtilisa
| Temp (°C) | Mean D ± SD for:
|
|||
|---|---|---|---|---|
| Wild-type PS 346 (SASP+)
|
Mutant PS 361 (SASP−)
|
|||
| Control | Cold shock | Control | Cold shock | |
| 85 | 25.0 ± 3 | 31.1 ± 4 | 8.1 ± 1 | 10.4 ± 1 |
| 90 | 15.1 ± 2 | 18.6 ± 1 | 4.0 ± 1 | 5.5 ± 1 |
| 95 | 8.5 ± 1 | 2.9 ± 0.4 | 3.3 ± 0.6 | 2.5 ± 0.5 |
| 100 | 5.2 ± 0.6 | 1.8 ± 0.3 | 2.4 ± 0.4 | 2.2 ± 0.3 |
a
The effect of sublethal cold pretreatment (cold shock) of sporulating cells of B. subtilis on the heat resistance of wild-type and mutant spores formed subsequently was assessed at 85, 90, 95, and 100°C and compared to spores formed from control unpretreated cells. The results are from two independent experiments. As shown by analysis of variance, the cold shock pretreatment results are significantly different from the corresponding results for controls (P < 0.05 for all the heat kill temperatures tested).