A joint team of Spanish and German researchers studying a former uranium mine says it has identified a bacterium capable of absorbing uranium from water, a discovery that could offer a cheaper, more sustainable way to clean up radioactive contamination. The findings, first reported by the Spanish outlet El Confidencial, describe a microorganism isolated from mine water that appears able to bind the radioactive metal and pull it out of solution.
A Microbe That Feeds on Radioactive Metal
Uranium mines, even decades after closure, often leave behind acidic pools and groundwater laced with dissolved uranium and other heavy metals. These sites are notoriously difficult and expensive to remediate, typically requiring chemical treatment plants that must run indefinitely to keep contamination from spreading into rivers and aquifers.
The bacterium under study appears to interact directly with uranium ions in water, converting them into a form that is less soluble and easier to remove. According to the report, researchers observed the microbe thriving in samples taken directly from mine water with elevated uranium concentrations, suggesting it may have evolved specifically to tolerate — and exploit — the metal-rich environment.
How the Discovery Was Made
The research grew out of a collaboration between Spanish and German scientific teams examining water and sediment samples from a mine site in Spain, one of several European countries with a legacy of uranium extraction dating back to the mid-20th century. Spain’s Salamanca and Cáceres provinces, for example, host some of the continent’s largest known uranium deposits and a number of abandoned or partially reclaimed mining operations.
By sequencing microbial communities living in the contaminated water, the team identified a bacterial strain that stood out for its apparent affinity for uranium. In controlled laboratory tests, the bacterium reportedly reduced dissolved uranium levels in water samples, though researchers caution that the mechanism — whether the microbe absorbs uranium into its cells, precipitates it externally, or both — is still being characterized.
Why Uranium-Contaminated Water Is a Growing Problem
Radioactive water contamination is not limited to old mines. It also affects:
- Sites near decommissioned or damaged nuclear facilities
- Groundwater near active uranium mining and processing operations
- Industrial runoff in regions with legacy nuclear weapons production
- Areas affected by improper disposal of nuclear waste
Current remediation methods usually rely on chemical precipitation, ion exchange resins, or reverse osmosis — all effective but costly, energy-intensive, and often generating secondary waste that itself requires disposal. A biological alternative that uses naturally occurring microorganisms to pull uranium out of water could, in principle, be deployed at a fraction of the cost, particularly at remote or long-abandoned sites where infrastructure investment is hard to justify.
From Lab to Real-World Cleanup
Researchers involved in the project stress that the work is still in an early, exploratory phase. Isolating a promising microbe in the lab is a long way from deploying it at scale in an open mine or contaminated aquifer, where temperature, competing microorganisms, and fluctuating water chemistry can all affect performance.
Bioremediation using uranium-tolerant bacteria has been studied for years, but researchers say this strain’s apparent efficiency and its natural presence at a real contamination site make it a particularly promising candidate for further study.
Next steps typically include testing the bacterium’s performance across a wider range of uranium concentrations and water conditions, evaluating how the extracted uranium can be safely recovered or stored once bound to the microbe, and assessing whether the bacterium poses any ecological risks if introduced into new environments. Field trials, if the lab results hold up, would likely follow years down the line.
What Comes Next
The Spanish-German team has not yet published the findings in a peer-reviewed journal, according to the report, meaning the results have not been independently verified by outside experts — a standard and necessary step before the discovery can be considered scientifically confirmed. Researchers are expected to pursue further funding and collaboration to expand the study, including genetic analysis of the bacterium and pilot-scale tests at contaminated sites.
If confirmed and scaled successfully, uranium-consuming bacteria could eventually complement or replace some conventional water treatment methods at mining and nuclear sites across Europe, offering a lower-cost path to managing one of the more persistent environmental legacies of the nuclear age. For now, scientists describe the discovery as an encouraging early step rather than a ready-made solution.
