Properties of spores of Bacillus subtilis blocked at an intermediate stagein spore germination

Germination of mutant spores of Bacillus subtilis unable to degrade their c ortex is accompanied by excretion of dipicolinic acid and uptake of some co re water. However, compared to wild-type germinated spores in which the cor tex has been degraded, the germinated mutant spores accumulated less core w ater, exhibited greatly reduced enzyme activity in the spore core, synthesi zed neither ATP nor reduced pyridine or flavin nucleotides, and had signifi cantly higher resistance to heat and UV irradiation. We propose that the ge rminated spores in which the cortex has not been degraded represent an inte rmediate stage in spore germination, which we term stage I.