Investigation of bacterial spore structure by high resolution solid-state nuclear magnetic resonance spectroscopy and transmission electron microscopy

High resolution solid-state nuclear magnetic resonance spectroscopy (NMR) i n combination with transmission electron microscopy (TEM) of spores of Baci llus cereals, an outer coatless mutant B. subtilis 322, an inner coatless m utant B. subtilis 325 and of germinated spores of B. subtilis CMCC 604 were carried out. Structural differences in the coats, mainly protein of spores were reflected by NMR spectra which indicated also differences in molecula r mobility of carbohydrates which was partially attributed to the cortex. D ipicolinic acid (DPA) of spores of B. cereus displayed a high degree of sol id state order and may be crystalline. Heat activation was studied on spore s of B. subtilis 357 lux + and revealed a structural change when analysed b y TEM but this was not associated with increases in molecular mobility sinc e no effects were measured by NMR. (C) 2001 Elsevier Science B.V. All right s reserved.