A strain of a common fungus has extracted palladium from a meteorite crushed while growing inside the International Space Station, an important step towards the use of biological resources in space.
Scientists placed the powdered meteorite in a liquid culture in a sealed container and left it in microgravity for several weeks. When the sample returned to Earth, analysis showed measurable amounts of palladium dissolved in the liquid. Fungal cultures released more metals than bacterial species tested together.
This result strengthens the case for using microorganisms to process raw materials off Earth and reduces the need to launch any critical components from the ground.
Microgravity changes chemistry
On Earth, fluids circulate by convection. In orbit, that movement almost disappears. Metal ions do not mix freely and move slowly, which raises questions about whether biological extraction systems work reliably.
Experiments show that it can be done. Even without the addition of chemicals, the fungi drove the extraction in near weightlessness. The researchers also observed that purely chemical leaching behaved differently in orbit, sometimes releasing certain elements sooner than expected.
Of the 44 elements measured in the sample, 18 were drawn into solution with the help of microorganisms. Fungal cultures accounted for a significant portion of that release.
fungi are better than bacteria
Under the same orbital conditions, the species Penicillium simplicissimum proved to be more effective than the bacterium Sphingomonas desiccabilis. Palladium concentrations rose most rapidly when the fungus grew directly on meteorite particles.
Survey results We emphasize the importance of biological selection in biomining. Different microorganisms interact with minerals in different ways, and their performance in space does not simply reflect what happens in a laboratory on Earth.
How fungi work
Fungi change their surroundings chemically rather than mechanically. Many release carboxylic acids that bind to minerals and liberate metal ions. When these compounds accumulate in a closed system, dissolution can continue even if the cells and rock are not in constant contact.
Chemical analysis revealed another change. In the microgravity environment, this fungus increased its production of some organic acids and other small molecules. This suggests that spaceflight conditions influence microbial metabolism and influence future bioreactor design.
From small chambers to the space industry
Identical hardware works earth This allowed the researchers to isolate the role of gravity in the process. Despite the promising results, the experiment was conducted on a small scale. Scale-up requires tighter control of microbial growth, fluid dynamics, and metal recovery systems.
Engineers also need efficient ways to capture and purify molten metals in a closed loop.
This study builds on previous orbital biomining tests and adds new data points using authentic meteorite material. This shows that living systems will remain active partners in chemistry even in orbit, reshaping the way future crews think about how they will obtain critical materials during long-duration missions.