Microbes harvest metals from meteorites aboard space station

Scientists have shown that microbes can extract precious metals from meteorites in space, opening new possibilities for sustainable space exploration.

The findings come from the BioAsteroid experiment which was conducted onboard the International Space Station (ISS) at the end of 2020. The researchers investigated how bacteria and fungi interact with meteorite material under microgravity conditions, comparing the results with identical experiments conducted on Earth.

The study involved researchers from Cornell University, including Rosa Santomartino and Alessandro Stirpe, and the University of Edinburgh, including Charles Cockell.

BioAsteroid builds on the team’s earlier landmark space biology mission, BioRock, which showed that microbes could extract useful elements from terrestrial rocks in space. BioAsteroid adds key scientific knowledge about how microorganisms interact with rocks in space, particularly extraterrestrial materials.

The BioAsteroid experiment showed that precious elements such as palladium can be extracted from meteorites under microgravity conditions using the filamentous fungus Penicillium simplicissimum. The researchersfound that extraction efficiency depends on the element of interest, the rock substrate, and the microorganism used.

This is highly relevant for future space biomining scenarios and highlights an increasingly evident reality in the space microbiology community: due to their diversity and plasticity, predicting microbial response to space conditions a priori is very difficult, if not impossible, making experimental testing essential for future space applications.

The team also performed a thorough metabolomics analysis of the samples after spaceflight, to highlight the bioproduction of molecules of interest for future space biomanufacturing efforts, and to better understand the mechanisms involved in microbial response to microgravity during biomining. They demonstrated that both the fungus and the bacterium used in this experiment can interact with the extraterrestrial mineral surface in microgravity by forming biofilms and mycelium. 

These results are relevant in the context of developing sustainable human space exploration, in which crews may establish long-term settlements on planetary bodies such as the Moon or Mars. In these environments, resources will be scarce, and frequent resupply from Earth will be unviable, and the only sustainable solution will be to obtain resources locally. These insights may also support the development of more sustainable biomining strategies on Earth, contributing to reduced resource consumption and lower environmental impact compared to conventional extraction methods.

The research was supported by the United Kingdom Science and Technology Facilities Council, the Leverhulme Trust, the University of Edinburgh School of Physics and Astronomy and Edinburgh-Rice Strategic Collaboration Awards.