Canadian scientists have discovered a tiny alchemist in disguise, the bacterium Delftia acidovorans. When this microbe is infused within a toxic mixture of water-soluble gold, it excretes a molecule that both protects it from the elements while also transforming the poisonous ions into solid nanoscale gold particles. It's a discovery that could someday allow for the conversion of mine waste into gold, or the creation of gold structures with unique properties.
Details of this remarkable biochemical process were recently published the journal Nature Chemical Biology. The paper's authors, who work at McMaster University in Ontario, did not look specifically at the viability of using this particular stand of bacteria to grow gold from a liquid mixture, but noted that such processess are "distinctly possible."
In the paper itself, researchers Chad Johnston, Nathan Magarvey and colleagues noted that the "finding is the first demonstration that a secreted metabolite can protect against toxic gold and cause gold biomineralization."
Nature News explains more:
Using biochemical and genome analysis, the researchers discovered a set of genes and a chemical metabolite that were responsible for precipitating the gold. Bacteria engineered to lack the genes no longer formed dark haloes, and their growth was stunted in the presence of gold. The team also isolated a chemical produced by the unengineered bacteria that caused gold particles to precipitate out of a solution. The chemical was dubbed delftibactin.
The researchers suggest that the genes they identified are involved in producing delftibactin and shunting it outside the cell. By precipitating gold, D. acidovarans may keep the metal from entering its cells in solution. But Magarvey says that it is possible that D. acidovarans also uses other mechanisms to detoxify gold that breaches its cell walls.
Images: optimarc/Shutterstock, McMaster University.