TABLE 2.
Outgrowth and growth parameters of individual heat-treated B. subtilis PS832 spores in time-lapse imagesa
| Nutrient(s), treatment |
Time (min) of indicated eventb |
No. (%) of indicated events |
||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ΔTburst |
P value | ΔTFirstCellDivision |
P value |
T
Generation
|
P value | |||||||
| Temp (°C) | Time (min) | Median | IQR | Median | IQR | Median | IQR | Burst | First cell division | |||
| AGFK | ||||||||||||
| Untreated | 219.8 | 106.5 | 192.0 | 81.0 | 250.6 | 91.4 | 159 (86.4) | 172 (93.5) | ||||
| 65 | 30 | 204.8 | 89.5 | 0.13 | 163.0 | 58.5 | < 0.01 | 210.5 | 94.1 | < 0.01 | 175 (81.0) | 205 (94.9) |
| 150 | 205.7 | 62.1 | < 0.01 | 179.5 | 58.0 | 0.14 | 288.1 | 230.9 | < 0.01 | 235 (89.4) | 231 (87.8) | |
| 300 | 239.3 | 118.7 | 0.14 | 167.0 | 62.0 | < 0.01 | 218.8 | 88.5 | < 0.01 | 196 (83.8) | 189 (80.8) | |
| 70 | 30 | 229.8 | 145.5 | 0.23 | 179.0 | 85.3 | 0.64 | 241.8 | 66.7 | 0.67 | 183 (89.3) | 173 (84.4) |
| 150 | 222.3 | 93.6 | 0.61 | 150.0 | 44.8 | < 0.01 | 189.4 | 57.3 | < 0.01 | 188 (83.2) | 190 (84.1) | |
| 300 | 287.8 | 145.4 | < 0.01 | 242.5 | 87.5 | < 0.01 | 371.6 | 149.2 | < 0.01 | 163 (76.5) | 117 (54.9) | |
| 75 | 30 | 197.9 | 118.0 | 0.02 | 186.0 | 55.0 | 0.37 | 206.9 | 58.9 | < 0.01 | 186 (88.2) | 185 (87.7) |
| 150 | 284.9 | 124.7 | < 0.01 | 201.0 | 72.8 | 0.03 | 232.7 | 103.8 | 0.12 | 130 (67.0) | 120 (61.9) | |
| 300 | 269.8 | 102.6 | < 0.01 | 177.5 | 54.0 | 0.29 | 183.0 | 60.6 | < 0.01 | 74 (52.1) | 75 (52.8) | |
| 80 | 15 | 234.8 | 93.9 | 0.05 | 211.0 | 73.8 | < 0.01 | 293.2 | 216.2 | < 0.01 | 162 (64.5) | 162 (64.5) |
| 30 | 271.9 | 125.4 | < 0.01 | 179.0 | 80.0 | 0.53 | 246.9 | 114.2 | 0.94 | 83 (52.5) | 77 (48.7) | |
| 60 | 307.0 | 196.3 | < 0.01 | 206.0 | 96.5 | 0.03 | 204.1 | 61.0 | < 0.01 | 54 (21.1) | 53 (20.7) | |
| 150 | 499.8 | 34.0 | < 0.01 | 331.0 | 49.0 | 0.03 | 222.4 | 0.0 | 0.70 | 3 (3.4) | 2 (2.2) | |
| 300 | 1 (0.7) | 0 (0) | ||||||||||
| l-Valine | ||||||||||||
| Untreated | 0 (0) | 0 (0) | ||||||||||
| 75 | 30 | 584.8 | 261.0 | 519.9 | 35 (34.7) | 1 (1.0) | ||||||
| 150 | 0 (0) | 0 (0) | ||||||||||
| 300 | 0 (0) | 0 (0) | ||||||||||
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.
ΔTburst, time between TPhaseDark (time of appearance of phase-dark spore) and TBurst (time of escape of cell from spore coat); ΔTFirstCellDivision, time between TBurst and TFirstCellDivision (time of first cell division); TGeneration, time between the first division and the end of the linear part of the log2(area)-versus-time plot; IQR, interquartile range.