dipicolinsyre

Dipicolinic acid, also known as dipicolinsyre, is a heteroaromatic dicarboxylic acid with a pyridine ring bearing carboxyl groups at the 2- and 6-positions (2,6-pyridinedicarboxylic acid). It is a major constituent of bacterial endospores and is found in high concentrations in spores of Bacillus, Clostridium and related genera. In spores, dipicolinic acid is typically present as the calcium complex calcium dipicolinate (CaDPA), which can account for a substantial fraction of the spore’s dry weight.

Biological role and significance are predominantly tied to spore resistance. The CaDPA complex helps dehydrate the spore core, stabilizing DNA and enzymes and contributing to resistance against heat, desiccation and chemical damage. This property makes dipicolinic acid a distinctive marker of mature bacterial spores.

Analytically, dipicolinic acid serves as a useful biomarker for spore detection and enumeration. Many assays detect the release or complexation of DPA after spore lysis; a common approach uses the luminescence of terbium–dipicolinate complexes, which enables sensitive and rapid quantification of spores in samples.

Chemically, dipicolinic acid acts as a versatile ligand in coordination chemistry and materials science, forming stable complexes with a range of metal ions. It is employed in ligand design and in some industrial applications including the preparation of metal–organic frameworks and related compounds.

Safety and handling are guided by standard laboratory practices for organic acids. Dipicolinic acid is primarily an irritant, and appropriate protective equipment and containment are recommended to minimize exposure.