Today's SP, page-24

Geologists have discovered bacteria on a patch of earth in regional Queensland that takes natural traces of gold and turns them into nuggets.
The discovery, according to University of Adelaide associate professor Frank Reith, means mining companies could turn tailings dams from a liability into an asset by recovering and reprocessing leftover gold.



A 'ground-breaking' study
Kilkivan landowner John Parsons, a former mine manager who took over the disused mine site in the 1990s, is now a co-author of two research papers based on bacteria found in his soil.
He explained the bacteria worked to filter out other minerals such as silver and copper to "build these little nuggets, grain by grain, layer by layer by layer".
Last year he worked with Association Professor Reith, as well as the University of Adelaide's Jeremiah Shuster, Swedish researcher Geert Cornelis, and University of Queensland scientist Gordon Southam, to unearth how long the bacterial refining process took, and published in the journal Chemical Geology.
Associate Professor Reith described it as "a ground-breaking study".
"For the first time, we actually have an estimation of how fast these things can happen in the natural environment," he said.
"We know it for a lot of other elements, but we had very little knowledge about gold until we put our work together with [other research]."
The bigger picture
Associate Professor Reith said the bacteria not only had the power to change recycling practices, but to turn gold mine tailings dams from a liability into an asset.
"In a lot of mines there's tailing materials and waste materials, and gold is lost there," he said.
"With current technology, we can't recover it. If you can make a recoverable resource from those parts, then you're adding to the bottom line of any mine."