Microbial Alchemy Produces 24-karat Gold
Metal tolerant bacteria called Cupriavidus metallidurans are able to produce 24-karat gold from a useless liquid gold-chloride substance. In the presence of this toxic gold substance the bacterium begins a series of mechanisms to defend itself and maintain cellular integrity which ends up reducing the toxic material into a nano-particulate metallic gold.
The bacterium actually has a gold specific operon within its genes that activates these mechanism and according to researcher Frank Reith, this can be used as mineral detectors and find new gold deposits.
This bacteria was actually discovered a few years ago but now artists are using the gold producing bacterium in an art exhibit and have discovered new found metal tolerance levels. Adam Brown, the associate professor of electronic art and intermedia, discovered that the bacteria can survive in levels of toxicity 25 times larger than previously recorded. He actually discovered this in one of his art installations "The Great Work of the Metal Lover" where the bacteria produces gold in front of the audience.
Though it still takes about a week for it to produce a nugget, this is essentially microbial alchemy. Producing gold nuggets on a small scale like in this art installation is one thing but to increase the scale of an operation like this would lead to diminishing returns
Via Science Daily