Molecular identification of an endosymbiotic bacterium associated with pederin biosynthesis in Paederus sabaeus (Coleoptera: Staphylinidae).

Biosynthesis of the structurally complex hemolymph toxin pederin is an eminent character of Paederus females. For that capability, however, they rely on endosymbiotic bacteria that are lacking in aposymbiotic females. The bacterial inhabitants of the two phenotypes in Paederus sabaeus are evaluated in a PCR-based analysis of 16S rDNA. A certain fragment, which is not found in aposymbiotic females, is highly dominant in the other, biosynthesizing females and thus identifies the endosymbiont. Its DNA sequence reveals a member of the gamma subdivision of the Proteobacteria that is clustered within the genus Pseudomonas (sensu stricto) as it is most closely related to Pseudomonas aeruginosa. These bacteria appear as the hypothesized common producers of pederin and the pederin family of analogs from marine sponges.