As humanity sets its sights on the stars, there’s one tiny yet indispensable companion we can’t afford to overlook: microbes. But here’s where it gets controversial—could these microscopic organisms not only survive but thrive in space, becoming our secret weapon for sustainable exploration? The answer might lie in a groundbreaking experiment aboard the International Space Station (ISS), where researchers are uncovering how microbes could revolutionize our approach to deep-space missions.
Microbes are everywhere—on our skin, in our bodies, and even in the food we eat. Leaving them behind isn’t an option, so understanding how they behave in space is crucial. But what if they could do more than just survive? What if they could help us extract essential resources from celestial bodies like asteroids and meteorites? This is where microorganisms like bacteria and fungi come into play. They possess a unique ability to harvest vital minerals from rocks, potentially offering a sustainable solution to the challenge of transporting resources from Earth.
In a collaborative effort between Cornell University and the University of Edinburgh, scientists conducted an experiment aboard the ISS to study how microbes extract platinum group elements from meteorites in microgravity. The results were eye-opening. And this is the part most people miss—certain fungi, known as ‘biomining’ fungi, excel at extracting palladium, a valuable metal, while their absence significantly hinders nonbiological extraction processes in space. This discovery, published in npj Microgravity on January 30, highlights the potential of microbes as spacefarers’ allies.
Led by Rosa Santomartino, an assistant professor of biological and environmental engineering, and co-authored by Alessandro Stirpe, a microbiology research associate, the study focused on two species: the bacterium Sphingomonas desiccabilis and the fungus Penicillium simplicissimum. These microbes were tested on L-chondrite asteroid material as part of the BioAsteroid project, spearheaded by astrobiologist Charles Cockell. The goal? To understand not just what they extract, but how they do it in the unique conditions of microgravity.
‘This experiment is likely the first of its kind on the ISS involving meteorites,’ Santomartino explained. ‘We aimed to balance specificity and generality to maximize its impact. These species extract different elements, so we wanted to uncover the mechanisms while keeping the findings broadly applicable. After all, microbial behavior in space is still shrouded in mystery.’
The key to their resource-harvesting prowess lies in carboxylic acids, carbon molecules produced by the microbes that bind to minerals and facilitate their release. However, here’s where it gets even more intriguing—many questions remain about how this process works in space. To address this, the team conducted a metabolomic analysis, examining the biomolecules produced during the experiment. NASA astronaut Michael Scott Hopkins performed the ISS experiment, while a control version was conducted on Earth for comparison.
Analyzing the vast dataset—which included 44 elements, 18 of which were biologically extracted—Stirpe noted, ‘We dissected the data element by element, asking: Does extraction differ in space versus Earth? Does it vary with bacteria, fungi, or both? While we didn’t find massive differences, some were strikingly significant.’
One standout finding was the fungus’s enhanced production of carboxylic acids in space, which boosted the extraction of palladium, platinum, and other elements. Interestingly, nonbiological leaching—a process without microbes—was less effective in microgravity, while microbial extraction remained consistent across both space and Earth environments.
‘In these cases, microbes don’t necessarily improve extraction but maintain a steady level regardless of gravity,’ Santomartino explained. ‘This isn’t limited to palladium; it applies to various metals, though not all. The extraction rate varies widely depending on the metal, microbe, and gravity conditions—a complex but fascinating result.’
Beyond space exploration, this research has terrestrial applications, such as efficient biomining from resource-scarce environments or mine waste, and fostering sustainable biotechnologies for a circular economy. However, Santomartino cautions against expecting quick answers. Here’s the bold truth—space’s impact on microbes is incredibly complex, with too many variables to provide a one-size-fits-all explanation. ‘It’s a beautiful challenge,’ she added. ‘The diversity of bacteria, fungi, and space conditions means we’re just scratching the surface.’
Supported by the United Kingdom Science and Technology Facilities Council, the Leverhulme Trust, and other institutions, this research opens doors to further exploration. But the question remains: Can we fully harness microbes’ potential in space, or will their behavior continue to surprise us? What do you think—are microbes the unsung heroes of space exploration, or is their role still too uncertain? Share your thoughts in the comments!
For more details, read the full study: Testing Microbial Biomining From Asteroidal Material Onboard The International Space Station.
