FIG 2.
Levels of AMP, 3PGA, and Pi in dormant spores of B. megaterium and B. subtilis incubated in water for different times and at different temperatures. Spores of the GR-less strains B. megaterium GC614 (filled symbols) or B. subtilis FB73 (open symbols) were prepared (on plates for B. subtilis spores), incubated in water at 4°C (circles), 37°C (triangles), or 50°C (squares); small molecules were extracted, extracts were processed, and levels of AMP (A), 3PGA (B), and Pi (C) were determined by 31P NMR as described in Materials and Methods. Values shown are averages from duplicate determinations in two separate experiments, and individual values for 3PGA and Pi did not deviate by more than 9% from average values; individual values for AMP in B. megaterium and B. subtilis spores did not deviate by more than 15 and 27%, respectively, from average. Note that values on the vertical axes in B and C are a log scale. There were no detectable NMR peaks from ADP or ATP in samples from B. subtilis and B. megaterium spores, and this allowed estimates that levels of ADP and ATP were ≤20% and 9% of AMP levels in all B. subtilis and B. megaterium spore samples, respectively.