Microbes Mine Metals in Space: ISS Experiment Reveals Biomining Potential
Microbes Demonstrate Potential for Asteroid Mining in ISS Experiment
The quest for sustainable space exploration hinges on the ability to utilize resources found beyond Earth. A recent experiment aboard the International Space Station (ISS) has demonstrated the potential of using microbes – specifically bacteria and fungi – to extract valuable metals from asteroid material, a process known as biomining. The findings, published on , in npj Microgravity, suggest a pathway towards greater self-sufficiency for future space missions and offer potential benefits for terrestrial mining practices.
The experiment, part of the larger BioAsteroid project, a collaboration between the University of Edinburgh and the European Space Agency (ESA), investigated how microorganisms interact with rock under microgravity conditions. Researchers deployed “biomining reactors” to the ISS in late /early . These reactors contained samples of an L-chondrite asteroid, a common type of stony meteorite, and were inoculated with Sphingomonas desiccabilis, a bacterium, and Penicillium simplicissimum, a fungus.
These particular microbes were selected for their ability to produce carboxylic acids. These acids play a crucial role in biomining by binding to minerals within the rock and effectively releasing them. “These are two completely different species, and they will extract different things,” explained Rosa Santomartino, an assistant professor of biological and environmental engineering at Cornell University’s College of Agriculture and Life Sciences, and a lead researcher on the study. “So we wanted to understand what and how, but keep the results relevant to a broader perspective, because not much is known about the mechanisms that influence microbial behavior in space.”
The experiment was conducted in parallel with a control group on Earth, allowing researchers to compare the effects of microgravity on the biomining process. NASA astronaut Michael Scott Hopkins performed the experiment aboard the ISS, while the Cornell and University of Edinburgh teams ran the corresponding tests in their laboratories. Analysis of the results revealed that 18 out of 44 different elements were extracted through biological processes.
Interestingly, the microbial extraction rates remained relatively consistent between the Earth-based and ISS experiments. However, the study revealed distinct changes in the metabolic activity of the microbes in microgravity, particularly within the fungal samples. Penicillium simplicissimum, for example, increased its production of carboxylic acids in the absence of Earth’s gravity, leading to enhanced extraction of palladium, platinum, and other valuable elements.
Conversely, non-biological leaching – a chemical process used to dissolve metals – proved less effective in microgravity compared to its performance on Earth. “In these cases, the microbe doesn’t improve the extraction itself, but it’s kind of keeping the extraction at a steady level, regardless of the gravity condition,” Santomartino noted. “And this is not just true for the palladium, but for different types of metals, although not all of them.”
The implications of this research extend beyond space exploration. Biomining is already employed on Earth as a more environmentally friendly and cost-effective alternative to traditional mining methods, which often rely on heavy machinery, fire, and significant human labor. As Charles Cockell, professor of astrobiology at the University of Edinburgh and senior author of the study, previously stated, bioremediation and bioleaching are “environmentally friendly, and produces fewer toxins,” requiring “low energy demand.”
For future lunar and Martian missions, biomining could enable astronauts to extract essential minerals from local regolith – the loose surface material – to create building materials, tools, and other necessary resources, significantly reducing reliance on costly and logistically challenging resupply missions from Earth. The potential applications also include the development of technologies for extracting metals from resource-limited environments or mine waste here on Earth, potentially contributing to a more circular economy.
However, researchers caution that further investigation is needed to fully understand the complex interplay between microbial behavior and the space environment. “Depending on the microbial species, depending on the space conditions, depending on the method that researchers are using, everything changes,” Santomartino said. “Bacteria and fungi are all so diverse, one to each other, and the space condition is so complex that, at present, you cannot give a single answer.”
The BioAsteroid project and subsequent research represent a significant step towards realizing the potential of biomining for both space exploration and terrestrial applications. While challenges remain, the successful demonstration of microbial metal extraction in microgravity offers a promising glimpse into a future where resources can be sustainably harvested from the vast reserves of asteroids and other celestial bodies.
Further Reading: Cornell Chronicle, npj Microgravity.