Finding new deposits of platinum is proving difficult. The metal is of industrial importance. Platinum is a dense, malleable, ductile, highly unreactive, precious, gray-white transition metal. The heavy metal is utilized in catalytic converters, electrodes, thermometers, and it is a common metal for jewelry.
Platinum is cycled through the environment and bacteria play a key role in this process. Researchers have been focusing on the study of the associated bacteria, in an attempt to find different deposits of platinum and related metals like palladium.
Recent geochemical research has challenged the view that platinum only forms under high pressure and high temperature, deep underground. The prevailing view was that a combination of weathering and uplift then brought the metals above ground.
The new research indicates that biofilms (special bacterial communities, where the bacteria live as if they are one ‘organism’) are associated with platinum deposits. There appears to be an association with the bacteria in concentrating the metallic elements, by processing them metabolically, and also with dispersing the deposits. Confirmatory laboratory studies have shown populations of bacteria can form nuggets of platinum and related metals.
To show this occurring in the natural state, researchers need to locate newly formed grains of platinum in soils, together with the biofilm communities and DNA. This can be, scientists hope, the basis of a detection system along the lines of: ‘find the bacteria, you may find the platinum.’
Methods to track down the organisms involve a combination of field work and scanning electron microscopy, followed by DNA sequencing.
The findings, from the University of Adelaide, are published in the journal Nature Geoscience, in a study titled “Biological role in the transformation of platinum-group mineral grains.”
