Sonic disruption of spores of Bacillus cereus

SUMMARY: The sonic disruption of spores of Bacillus cereus gives multi-hit kinetics. The flrst hit destroys the exosporium, which protects the spore body from destruction; the second hit destroys the spore body. Spores which have been stripped oftheir exosporia are still viable and heat resistant. From the rate of release during genic tmatment it appears that alanine raceITLsse, adenosine deaminase and hexos-amine are located in the exosporium while ribosidase is in the spore body. The rate of release of dipicolinic acid does not identify it $ location. Since the discovery of alanine racemase in spores (Stewart & Halvorson, 1953) several other enzymes have been found in preparations of well-cleaned spores (reviewed by Halvorson & Church, 1957). Many of the enzymes in extracts of spores are particulate and heat-stable, but the location of the enzymes within the spore is somewhat obscure. Electron micrographs of thin sections of spores of BaciZZzM cmew (Robinow, 1958) show a large well-defined exo-sporium as the outermost structure surrounding the spore coat. The electron-dense spore coat, in turn, delimits what we shall refer to as the spore body