Floating within the International Space Station, minute pieces of a meteorite were submerged in liquid alongside fungal colonies, extracting palladium. This piece of L-chondrite from northwest Africa, sterilized and sent into space aboard a SpaceX Falcon-9 in December 2020, observed two microorganisms operating in weightlessness for 19 days, while another batch of samples was incubated on Earth. The fungus surpassed the bacterium and challenged microgravity chemistry.
This initiative, BioAsteroid, serves as a crucial examination of employing organisms to garner resources from space rocks. Rosa Santomartino from Cornell University spearheaded this groundbreaking ISS investigation on meteorites. The goal is to identify raw materials for prospective extraterrestrial habitats, as transporting them from Earth proves expensive. Asteroids contain precious metals like palladium and platinum, vital for electronics and catalytic converters. The challenge lies in extracting these components without terrestrial facilities.
Biomining on Earth utilizes microorganisms to extract 20% of the planet’s copper and considerable amounts of gold, sidestepping toxic chemicals. Santomartino’s team, in collaboration with Charles Cockell from the University of Edinburgh, selected two organisms: Sphingomonas desiccabilis, a bacterium effective in basalt biomining, and Penicillium simplicissimum, a recognized bioleacher but new to space application.
Astronaut Michael Scott Hopkins set the experiment in KUBIK incubators aboard the ISS. Examination of 44 elements revealed the fungus to be superior. In microgravity, P. simplicissimum improved palladium extraction by 550% compared to non-biological methods, retrieving nearly 12% of the palladium in 19 days, and also facilitated the release of ruthenium and platinum. The bacterium demonstrated minimal effect, frequently hindering leaching due to biofilm formation which protected the rock.
Unexpectedly, abiotic palladium leaching decreased 13.6-fold in microgravity compared to Earth. The fungus compensated for this, underscoring its vital role in future space mining, where the removal of microbes would be counterproductive. Metabolomic analysis indicated that P. simplicissimum increased carboxylic acid production in weightlessness, which could have applications in bioplastics or pharmaceuticals.
The economic prospects appear daunting. Present palladium prices would generate merely $10 in metal from the bioleaching setup. Omitting the fungus would cut this by 545%, emphasizing its significance. Santomartino’s team seeks to comprehend microbial mechanisms in space, considering the existing knowledge deficiency.
These results are a proof of concept rather than a business model but imply that biology can enhance physics and chemistry in low gravity, making microbes essential for sustaining extraterrestrial habitats. [Study link](https://www.nature.com/articles/s41526-026-00567-3)