Genome Mining Guided Identification of the Metallophore Delftichelin A from Delftia deserti

A targeted sequencing and genome mining approach for delftibactin-like biosynthetic pathways revealed three distinct biosynthetic gene cluster architectures (BGC del, dlc and dlp) encoded in genomes of members of the genus Delftia. Comparative metabolomic analysis guided the isolation and characterization of a yet unreported metallophore, delftichelin A from Delftia deserti DSM1621 (previously named Delftia acidovorans DSM1621). Prediction of BGC architecture and A domain specificity was in line with the structure analysis uncovering previously unreported differences in amino acid composition and modifications. Analysis of bioactivity and metal-binding characteristics demonstrated that delftichelin A shows a preferential affinity for ferric iron, while also exhibiting heavy metal detoxification mechanisms via oxidative degradation, analogous to those reported for the delftibactin family of compounds.