Induced release of dipicolinic acid from spores of Bacillus megaterium.

Conditions under which dipicolinic acid may be released from bacterial spores probably relate to the chemical state of the dipicolinic acid in the spore, to its physical location in the spore, and to its influence on the physiological properties of the spore. The latter aspect embraces the relation between release of dipicolinic acid and the viability of the spore, its heat resistance, and its refractility. It is known that dipicolinic acid is released physiologically during germination of bacterial spores (Powell and Strange, 1953), and that it can be extracted by boiling dilute mineral acid (Perry and Foster, 1955). Dipicolinic acid in spores of Bacillus cereus var. mycoides is also released by mechanical disruption of the spores (Rode and Foster, 1956; Powell and Strange, 1955; Young, 1959). Because dipicolinic acid is important in physiological and biochemical studies of spores, a systematic survey of treatments was undertaken with the object of releasing dipicolinic acid and, in some cases, correlating the release with the viability of the spores. To distinguish the release of dipicolinic acid from spores by means other than the normal physiological process of germination, the term "induced release" is employed.