Bioleaching of metals

During recent experiments conducted on the International Space Station, it was observed that a bacterium of terrestrial origin was capable of leaching light and heavy rare earth elements from basaltic rock. This will soon be reported in the scientific literature but further studies are necessary to understand how extensive this ability is within the species of bacterium, previously unreported to exhibit this activity, and the mechanism used. Once this fundamental knowledge has been gained, this project will use synthetic biology tools and techniques to optimise selective metal recovery and to domesticate the bacterium, with the aim of being able to use this bacterium in an industrial process with partners SEM.

The rare earth elements are critical metals; Scotland, the UK and Europe are hugely dependent on their supply from further afield. The criticality of such materials is a dynamic phenomenon, dependent on balancing usage, stocks and politics; the EU wide assessment in 2017 identified 27 critical raw materials. Within this study the 17 rare earth elements are grouped into the light REEs and the heavy REEs, both groups being of significant economic importance as they are vital to the manufacture of many hi-tech products. Light REEs have the highest supply risk to the EU of all critical raw materials, closely followed by heavy REEs, thus their recovery should be prioritised at every opportunity.