Meet Cupriavidus metallidurans, the ultimate tiny badass. This unassuming bacterium thrives in soil packed with toxic heavy metals—and in the process, it literally poops gold.
Scientists uncovered this wild ability in 2018, revealing how the bacterium survives in metal-rich environments. Copper and gold are toxic in excess, but C. metallidurans has evolved a genius workaround. It actually needs copper to survive, but too much of it is dangerous. That’s where a special enzyme, CupA, comes in—this molecular pump ejects excess copper, keeping the bacterium alive.
But when gold enters the mix, things get interesting. Copper-gold compounds are extremely toxic, so the bacterium switches strategies. Instead of using CupA, it activates a different enzyme, CopA, which transforms these compounds into something less absorbable. This allows C. metallidurans to neutralize the toxins while also producing tiny gold nuggets—yes, real gold—just outside its cells.
According to Professor Dietrich H. Nies, this survival strategy makes perfect sense. The bacterium has found a way to handle toxic metals while thriving in an environment with little competition. The result? Microbial alchemy.
This discovery not only reveals nature’s ability to adapt in extreme conditions but also opens doors to potential biotechnological applications. Could bacteria one day help us mine gold? Only time will tell. For now, Cupriavidus metallidurans holds the crown for the world’s most valuable poop machine.
