TABLE 1.
Germination parameters of individual heat-treated B. subtilis PS832 spores in time-lapse imagesa
| Nutrient(s), treatment |
Time (min) of indicated eventb |
No. of germination events (% germination) | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
|
T
1
|
P value | ΔTSlowLeakage |
P value | ΔTPhaseDarkening |
P value | ||||||
| Temp (°C) | Time (min) | Median | IQR | Median | IQR | Median | IQR | ||||
| AGFK | |||||||||||
| Untreated | 12.0 | 4.7 | 40.0 | 65.1 | 12.1 | 3.9 | 184 (100) | ||||
| 65 | 30 | 9.0 | 3.2 | < 0.01 | 15.0 | 29.1 | < 0.01 | 11.0 | 3.0 | < 0.01 | 216 (100) |
| 150 | 5.2 | 2.1 | < 0.01 | 5.0 | 12.9 | < 0.01 | 10.2 | 3.0 | < 0.01 | 263 (100) | |
| 300 | 4.0 | 0.0 | < 0.01 | 3.2 | 10.4 | < 0.01 | 11.1 | 4.0 | < 0.01 | 231 (98.7) | |
| 70 | 30 | 10.3 | 7.0 | < 0.01 | 19.1 | 36.4 | < 0.01 | 11.1 | 2.4 | < 0.01 | 204 (99.5) |
| 150 | 5.5 | 1.0 | < 0.01 | 3.9 | 9.9 | < 0.01 | 12.2 | 3.9 | 0.13 | 225 (99.6) | |
| 300 | 4.0 | 2.3 | < 0.01 | 3.0 | 6.9 | < 0.01 | 14.1 | 4.3 | < 0.01 | 213 (100) | |
| 75 | 30 | 8.0 | 2.0 | < 0.01 | 23.1 | 40.0 | < 0.01 | 13.1 | 3.8 | < 0.01 | 211 (100) |
| 150 | 6.0 | 2.1 | < 0.01 | 11.0 | 25.3 | < 0.01 | 17.1 | 5.9 | < 0.01 | 176 (90.7) | |
| 300 | 3.0 | 1.0 | < 0.01 | 4.0 | 10.0 | < 0.01 | 19.2 | 9.4 | < 0.01 | 126 (88.7) | |
| 80 | 15 | 7.0 | 4.1 | < 0.01 | 29.1 | 56.0 | 0.02 | 14.2 | 5.4 | < 0.01 | 231 (92) |
| 30 | 6.0 | 2.0 | < 0.01 | 59.5 | 99.4 | 0.04 | 15.2 | 6.9 | < 0.01 | 122 (77.2) | |
| 60 | 8.0 | 1.7 | < 0.01 | 66.0 | 304.1 | < 0.01 | 16.2 | 9.0 | < 0.01 | 153 (59.8) | |
| 150 | 10.0 | 1.0 | 0.19 | 48.0 | 140.0 | 0.53 | 16.1 | 18.1 | 0.42 | 11 (12.4) | |
| 300 | 0 (0) | ||||||||||
| l-Valine | |||||||||||
| Untreated | 7.5 | 1.0 | 11.1 | 22.0 | 13.3 | 5.1 | 112 (100) | ||||
| 75 | 30 | 7.0 | 1.0 | < 0.01 | 10.1 | 15.8 | 0.84 | 12.1 | 3.5 | < 0.01 | 99 (98) |
| 150 | 3.0 | 0.5 | < 0.01 | 7.0 | 37.5 | 0.32 | 15.1 | 10.4 | 0.40 | 75 (87.2) | |
| 300 | 3.0 | 1.0 | < 0.01 | 0.1 | 17.0 | 0.02 | 19.3 | 10.0 | < 0.01 | 61 (77.2) | |
As described in the legend to Fig. 5, B. subtilis PS832 spores were treated with various temperature-time conditions, followed by being germinated and grown on a MOPS-agarose pad with (10 mM each) AGFK and 10 mM l-valine. Data were collected by SporeTrackerX (ImageJ Macro) as described in Materials and Methods. The significance of differences between heat-treated groups and the untreated group was measured by the Mann-Whitney test.
T1, time when spore commitment occurred following exposure to germinant; ΔTSlowLeakage, time between T1 and TStartRelease (start of rapid Ca2+-DPA release); ΔTPhaseDarkening, time between TStartRelease and TPhaseDark (time of the appearance of the phase-dark spore); IQR, interquartile range.