Microbes may have the Midas touch
MERAIAH FOLEY
theglobeandmail.com
Associated Press
SYDNEY, AUSTRALIA — Researchers in Australia have uncovered evidence that a tiny microbe may have the Midas touch of Greek legend, capable of turning dust to gold.
Findings reported in the July 14 issue of the U.S.-based magazine Science suggest a bacteria known as Ralstonia metallidurans may play a key role in forming gold nuggets and grains.
A group of scientists led by German-born researcher Frank Reith collected gold grains from two Australian mines more than 3,000 kilometres apart, and discovered that 80 per cent of the grains had the bacteria living on them.
“What we found out suggests that bacteria can accumulate this gold,” Mr. Reith told The Associated Press in a telephone interview from his Australian office on Friday.
Mr. Reith said Ralstonia metallidurans act as microscopic soil scrubbers, soaking up heavy metals in their dissolved form and converting them into less toxic, solid forms.
“Heavy metals are toxic, not only to us but also to microorganisms, in elevated concentrations,” he said.
“It appears to be that the organism can detoxify its immediate environment of this toxic mobile gold and in this way gain a metabolic advantage,” he said. “That's why it would be present on these gold grains.”
Many scientists have questioned the possible microbial role in forming gold, maintaining instead that gold grains were either remnants of larger pieces or formed through chemical processes.
Mr. Reith said his findings provide the strongest evidence yet that bacteria could play a key role in creating solid gold, although the exact mechanism is not yet known.
“What we just wanted to show is that microorganisms are capable of contributing to the formation of gold nuggets and before that was always doubted,” Mr. Reith said. “I'm not saying that the organisms are the only way how gold nuggets in soils can form, but it's one of the ways.”
But home-alchemists be warned, pouring a bucket of Ralstonia metallidurans on your backyard won't create a gold mine.
“You have to have gold there first. If you don't, bacteria can't create gold,” Mr. Reith said. |
