A natural product that converts gold ions into gold particles is identified in a paper published online in Nature Chemical Biology. The study explains how this hardy bacterium survives in its unique environmental niche and provides new strategy for gold particle formation.
Delftia acidovorans is known to live within gold nuggets, though how the bacteria avoid gold-mediated toxicity was unknown. Nathan Magarvey and colleagues discover that a molecule excreted out of the bacteria cells is capable bringing gold ions together to form large gold aggregates that are no longer toxic. Bioinformatic analysis followed by natural product isolation identified the peptide-like delftibactin A as the active molecule.
Magarvey and colleagues show that this compound looks like a traditional siderophore - a class of molecules that bind to iron - and that the compound does indeed bind iron in in vitro experiments. However, the additional function of this molecule in reacting with gold ions, combined with the unusual environmental location of the bacteria, provide exciting evidence that this species has co-opted a common molecule to eliminate gold toxicity in nature.