Abstract
Dormant spores of Bacillus cereus T were examined by 31P nuclear magnetic resonance. Three peaks appeared at 3.48, 1.67, and 0ppm in the spectrum at an external pH value of 8.4. Two of them (1.67 and 0ppm) were observed also in the spectrum at pH 6.4. We tentatively assigned the peaks at 1.67 and 0ppm as the internal orthophosphate (Pi) and some species of phospholipids, respectively. The peak at 3.48ppm was not identified.
The internal pH value of the spores was estimated from the pH-dependent chemical shifts of the internal Pi peaks. No change in the internal Pi peaks was found at various pH values of the buffer from 8.4 to 6.4. The internal pH value calculated from the Pi chemical shifts was 6.5.
No peak corresponding to ATP nor NAD+ was found in the spores.
