Researchers find gold-digging bacteria

Scientists have been examining a species of bacteria that has an affinity for gold. It is possible that the bacterium could be used to detect hidden gold.

The bacterium is called Delftia acidovorans. What is unusual about this microorganism, ABC notes, is that it can secrete a molecule that binds to dissolved gold and turns it into shiny, solid gold (on a microscopic scale, that is). The usefulness of this is that either that the bacterium could be used to detect gold or, more likely, used to create gold nanoparticles. The discovery came about when scientists found communities of bacteria growing on gold grains in soil, according to an earlier report in The Week. It was later discovered that the bacteria have an ability to transform liquid gold into grains of gold. What happens in nature is that layers of bacteria dissolve gold into nanoparticles, which move through rocks and soils, and then deposit it in other places. This sometimes creates purer secondary gold deposits in cracks and crevices of rocks. The way that D. acidovorans carries out this transformative process is due to a protein, the Telegraph of India summarizes, that it carried. This is unusual because gold is normally toxic to bacteria (another exception is Cupriavidus metallidurans). The way this happens is through electrons passing into the gold, which functions to detoxify it. The bacterium then ingests the gold and secretes a solid pellet. The pellet has been named delftibactin. The research has been undertaken by University of Adelaide in Australia and the McMaster University in Canada. The findings have been published in the journal Nature Chemical Biology.