Studies of the release of small molecules during pressure germination of spores of Bacillus subtilis

Abstract

To measure rates of release of small molecules during pressure germination of Bacillus subtilis spores, and the role of SpoVA proteins in dipicolinic acid (DPA) release. Rates of DPA release during B. subtilis spore germination with pressures of 150 or 500 megaPascals were much higher in spores with elevated levels of SpoVA proteins, and spores with a temperature-sensitive mutation in the spoVA operon were temperature-sensitive in DPA release during pressure germination. Spores also released arginine and glutamic acid, but not AMP, during pressure germination. Pressure germination of B. subtilis spores causes release of many small molecules including DPA. SpoVA proteins are involved in the release of DPA, perhaps because SpoVA proteins are a component of a DPA channel in the spore's inner membrane. This work provides new insight into the mechanism of pressure germination of spores of Bacillus species, a process that has significant potential for usage in the food industry.