Scientists Discover Bacterium That Converts Heavy Metals from Soil into Solid Gold

Bacteria turning heavy metals into gold, nature’s very own alchemist! Illustration by the author.

Imagine a tiny organism that can turn pollution into treasure. Scientists have recently uncovered a bacterium, Cupriavidus metallidurans, that does exactly that . Living in soils rich in heavy metals like copper and gold, this microbe has evolved a remarkable survival trick: it detoxifies its environment by converting harmful gold ions into solid gold nanoparticles .

Here’s how it works. Gold in its ionic form is toxic to most life, but this bacterium uses specialized enzymes to transform the soluble gold into harmless metallic nuggets. Essentially, it “eats” the toxic gold compounds and excretes real, solid gold, though only in microscopic, nanometer-sized particles. In lab cultures, C. metallidurans can precipitate ~90% of soluble gold from a 100 µM AuCl₃ solution within hours, forming 10-40 nm particles mostly outside the cell.

This discovery isn’t just fascinating biology, it could have real-world applications. In the future, these bacteria could help recover gold from mine waste or electronic scrap, offering a greener alternative to chemical extraction methods . It also helps explain how nature naturally redistributes metals in soil over time.

While the amount of gold produced is tiny, the fact that life can perform what looks like real-life alchemy is nothing short of amazing. It’s a striking example of how evolution equips organisms to survive in extreme environments, and in doing so, accidentally creates something humans have coveted for thousands of years .

Reference:
Reith, F., Etschmann, B., Strahm, B., & Krauss, G. J. (2009). Mechanisms of gold biomineralization in the bacterium Cupriavidus metallidurans. Proceedings of the National Academy of Sciences, 106(42), 17757–17762. https://doi.org/10.1073/pnas.0904742106