FIG 6.

³¹P NMR spectra of small molecules from dormant GR-less B. megaterium spores either as just harvested or incubated in spent sporulation medium under various conditions. GR-less spores of B. megaterium GC614 were prepared in a fermentor, harvested, and purified as described in Materials and Methods. Samples of spores were taken and processed, and small molecules were extracted and purified, as described in Materials and Methods either without further incubation (A) or after 10 (B) or 30 (C) days of incubation at 50°C in spent sporulation medium containing 200 mM Tris-HCl buffer (pH 8.8) and 20 mM (NH₄)₂SO₄. ³¹P NMR spectra of the purified extracts were then acquired as described in Materials and Methods. Peaks are labeled as determined by positions of known standards added to spore extracts. Note that the appearance of the NMR peak just upfield of PGA in panel B was quite variable, and its identity is not clear.