Table 1.
Percentage of superdormant (SD) spores in various isolation conditions and proposed superdormancy mechanisms.
| SD spore type | Germination stimulus | Species | ca. % SD spores | Proposed superdormancy mechanisms | Reference |
|---|---|---|---|---|---|
| Valine (10 mM) | B. subtilis | 1.1 | Chen et al., 2014 | ||
| Valine (10 mM) | B. subtilis | 4 | Zhang et al., 20121 | ||
| Valine (10 mM) | B. subtilis | 3.8 | Ghosh and Setlow, 2009 | ||
| Valine (300 μM) | B. subtilis | 58 | Ghosh and Setlow, 2009 | ||
| 10 × LB medium2 | B. subtilis | 0.7 | Ghosh and Setlow, 2009 | ||
| AGFK3 | B. subtilis | 12 | Permanent cause: lower GR | Ghosh and Setlow, 2009 | |
| AGFK4 | B. subtilis | 6 | levels Transient cause: | Zhang et al., 20121 | |
| Nutrient-SD | Glucose (10 mM) | B. megaterium | 3.5 | activation status | Ghosh and Setlow, 2009 |
| Glucose (200 μM) | B. megaterium | 38 | (Ghosh et al., 2009, 2012; | Ghosh and Setlow, 2009 | |
| 10 × LB medium | B. megaterium | 0.5 | Wei et al., 2010; | Ghosh and Setlow, 2009 | |
| Alanine (50 mM) | B. cereus | 5.3 | Zhang et al., 2012) | Ghosh and Setlow, 2010 | |
| Inosine (5 mM) | B. cereus | 2.3 | Ghosh and Setlow, 2010 | ||
| Inosine (250 μM) | B. cereus | 12 | Ghosh and Setlow, 2010 | ||
| Inosine (5 mM, no heat activation) | B. cereus | 12 | Ghosh and Setlow, 2010 | ||
| Ca2+DPA-SD | Ca2+-DPA (60 mM) | B. subtilis | 0.9 (0.5–1.6) | Coat defect, low levels of CLE CwlJ | Perez-Valdespino et al., 2013 |
| Dodecylamine-SD | Dodecylamine (1.2 mM) | B. subtilis | 0.4 (0.1–1.1) | Not clear | Perez-Valdespino et al., 2013 |
| High pressure SD | No reported isolation | Different to nutrient superdormancy | Wei et al., 2010 | ||
Unless stated otherwise, heat activation was applied prior to nutrient germination for different species: B. subtilis: 75°C, 30 min; B. megaterium: 60°C, 15 min; B. cereus: 65°C, 20 min. 1Spores were heat activated at 70°C for 30 min. SD spore percentages were calculated based on observation of >440 spore for listed cases; 2LB medium: Luria-Bertani medium; 3AGFK (12 mM L-asparagine, 13 mM D-glucose, 13 mM D-fructose, 12.5 mM KPO4 buffer [pH 7.4]); 4AGFK (10 mM L-asparagine, 10 mM D-glucose, 10 mM D-fructose, 10 mM KCl in 25 mM KPO4 buffer [pH 7.4]).