Scientists from the University of Adelaide in Australia have discovered the key role played by certain bacteria in the formation and movement of platinum and related metals in surface environments.
University of Adelaide School of Biological Sciences senior lecturer Dr Frank Reith said: "These platinum group elements are strategically important metals, but finding new deposits is becoming increasingly difficult due to our limited understanding of the processes that affect the way they are cycled through surface environments.
"This improved bio geochemical understanding is not only important from a scientific perspective but we hope will also lead to new and better ways of exploring for these metals."
Platinum and palladium, the platinum group metals are used in various industrial processes.
The latest project is a partnership with Monash University and Mineral Resources Tasmania along with the University of Queensland, University of Western Australia, RMIT and the Federal Institute for Geosciences and Natural Resources in Germany.
"Traditionally it was thought that these platinum group metals only formed under high pressure and temperature systems deep underground, and that when they were brought to the surface through weathering and uplift, they just sat there and nothing further happened to them," Dr Reith added.
As part of the research, the scientists linked specialised bacterial communities that are found in biofilms on the grains of platinum group minerals at three separate locations across the globe.
It was highlighted that nuggets of platinum and related metals can be reformed at the surface through bacterial processes.
Platinum group elements from Brazil, Colombia and the Australian state of Tasmania have been considered to carry out the study.
Live bacterial biofilms were found on mineral grains from all three sites using scanning electron microscopy.
It was found that the mineral grains found at the Brazil site were bio-organic in origin. This supported the role played by the bacteria in the secondary formation of platinum grains.