TABLE 4.
Requirements for Ca2+–DPA-triggered germination of quintuple-mutant sporesa
| Germination medium | Titer (CFU/ml/OD600 unit)b |
|---|---|
| Water | 6 × 104 |
| 50 mM Ca2+–DPA | 2.2 × 107 |
| 50 mM CaCl2 | 5 × 104 |
| 50 mM DPA | 1.4 × 106 |
| 50 mM Mg2+–DPA | 8 × 105 |
| 50 mM K+–DPAc | 3 × 106 |
a
Spores of strain FB85 were heat activated, incubated in various germination media for 1 h at room temperature, plated on LB agar, and incubated overnight at 37°C prior to colony counting.
b
The titers represent the means of two different experiments, and the values in these two experiments were within 40% of each other. Similar values were also obtained using two different preparations of spores.
c
Identical results were obtained when [K+] was adjusted to 100 or 50 mM.