A team of researchers from both Texas and Brazil have collaborated on a paper called Copper Mining Bacteria: Converting toxic copper ions into a stable single atom copper.
The paper reveals how bacteria from copper mines can naturally extract metal ions and transform them into a valuable commodity.
The research was originally inspired by a noticeable change in colour of the bacteria in question.
“The discovery of an isolate from the genus Bacillus that is able to produce monoatomic copper inside the cells was recorded initially based on the visual observation of colour changes in the bacterium growth media with CuSO4 (copper sulphate) after 48 hours,” the paper stated.
“The change in the growth media from green (CuSO4 + bacteria) to an ‘orange colour’ represented the transformation from CuSO4 to Cu0 (copper oxide).”
The study found the discovery of interest because the process of mining, smelting and producing copper can be dangerous due to the release of sulphur dioxide and nitrogen dioxide.
This finding, by itself, implies that microbes can extract copper from contaminated sites and, thus, improve sustainability by eliminating the use of toxic solvents such as sulphuric acid (used for leeching copper from ore).
Debora Rodrigues, a professor from the University of Houston, said the result could open doors to plenty more like-minded studies into sustainable copper production.
“We have only worked with one bacterium, but that may not be the only one out there that performs a similar function,” Rodrigues said.
“The next step for this particular research is harvesting the copper from these cells and using it for practical applications.”
Approximately 20 million tonnes of copper were produced in 2020, along with all the environmental impacts that come with copper production.
These can include land degradation, ground and surface water pollution as well as reports of more acidic rain damaging crops downwind from mines.
While the valuable commodity is also used in the decarbonisation of many industries, in products such as electric vehicles and lithium batteries, the discovery of this bacteria’s capabilities has the potential to reduce copper production emissions dramatically.