dipicolinic

Dipicolinic acid, or dipicolinate, is 2,6-pyridinedicarboxylic acid, a small aromatic dicarboxylic acid. It is notable for its abundance in the spores of certain bacteria, especially Bacillus and Clostridium species, where it accumulates in the spore core.

In bacterial spores, dipicolinic acid forms a stable complex with calcium, known as calcium dipicolinate. This compound is a major component of the spore core and can constitute a significant portion of the spore’s dry weight. The calcium dipicolinate complex is associated with the spores’ extreme resistance to heat and desiccation. It is believed to contribute to core dehydration and to stabilization of macromolecules such as DNA and proteins, aiding spore survival under adverse conditions. Dipicolinic acid is synthesized during sporulation and gradually accumulates in the dormant spore; during germination, it is released as metabolism resumes.

From an analytical and microbiological perspective, dipicolinic acid serves as a practical biomarker for bacterial spores. Several assays detect DPA directly or via the calcium complex, often leveraging the fluorescence of calcium–dipicolinate or using chromatographic methods after appropriate sample preparation. The presence and quantity of DPA can aid in estimating spore burden or monitoring germination in laboratory or applied settings.

Safety considerations: dipicolinic acid is a chemical used in research contexts and should be handled with standard laboratory safety practices and appropriate material safety data considerations.