Scientists have announced the discovery of a bacteria that appears to be able to extract dissolved gold from a solution and deposit it as a solid gold nugget.
The bacteria, called Ralstonia metallidurans, was identified by Frank Reith of Australian National University and his colleagues as the common denominator among bacteria comprising a dried organic biofilm found on the surface of gold grains collected from a park and gold mines in southern New South Wales and northern Queensland, Australia.
The gold was found in association with pyrite (or fool's gold) in quartz and arsenopyrite.
Reith then isolated and grew more of the bacteria in the lab and used a scanning electron microscope to observe gold precipitation in the presence of the microbe. It took just eight hours for a small grain to form.
Testing a theory for how gold grains form when it starts out dissolved in a liquid solution, he confirmed that the bacteria play an important role in the formation of this type of gold nugget. Others thought the grains might come out of solution by some other chemical or leftover process.
"A unique attribute of R. metallidurans is that it is able to survive in concentrations of gold that would kill most other micro-organisms," Reith said.
It is still unknown exactly how the bacteria help to precipitate the gold grains, but is possible that the microbe screens out the gold as part of an effort to detoxify its immediate environment. Metals like gold are toxic to most bacteria.
The finding, published in the latest issue of the journal Science, could suggest opportunities for bio-processing of gold ores, Reith said.
Just imagine. Extracting gold from seawater. Or river water. Why you could make a …..
Hold my calls, I'll be in the lab.
