Microbes could be used in future human space settlements, extracting metals and rare elements from rocks, according to a researcher who designed the world’s first mining experiment in space.
“You can think of microbes as miniature miners if you want, going into the rocks and getting all the good things we need to build a civilization,” said Professor Charles Cockel, an astrobiologist at the University of Edinburgh.
If humans are ever settling in space or on other planets, they will probably need to find ways to effectively find and gather resources in an alien environment. Digging will be a key technology in these efforts.
Cockle said Oddities and oddities host Bob MacDonald that microbes are currently being used on Earth to extract valuable materials from rocks
“If these rocks contain gold or copper, then we can use microbes to break down these materials,”
This direct result was very exciting because it was the first demonstration of extraterrestrial extraction.– Prof. Charles Cockel, University of Edinburgh
Human miners crush rocks and add liquid – usually water – to activate microbes asleep in the ore.
The microbes then use chemical processes to break down the rocks – essentially digesting them – to access nutrients such as phosphorus and nitrogen. Precious metals and minerals can be a bacterial waste product.
“The infiltrate, which is the liquid that comes out of the rocks, contains the elements you want to get,” Kokel added. These elements can then be easily extracted from the filtrate for use.
On Earth, mining companies use bacteria to extract about 20 percent of the world’s copper and five percent of our planet’s gold.
Potential complicating factors at low gravity
Kokel wanted to see if the microbes would do the same job in space. In 2019, he managed to send an experiment to the International Space Station to test this. He has just published the results of his research in the journal Nature Communications.
The question he was particularly concerned about was whether the space station’s microgravity environment would cause microbial cells to behave differently in the processing of minerals in space than on Earth.
In particular, his concern was whether the lack of gravity would mean that bacterial cells could not move to the right places in the rock and the aqueous suspension, or would disrupt the normal circulatory processes that cause liquids around the rock particles to mix on Earth. allows microbes to access them. Whether rock-eating microbes will thrive and multiply in space was also a problem.
“A lot of people have shown that gravity really affects microbial growth in space,” Cockle said. “So we were just testing whether the gravity of Mars and microgravity, for example, and asteroids would change the way biomining happens.”
Mining experiment aboard the ISS
In their space station experiment, they tested three different bacterial species under different gravitational conditions to mimic the gravity of an asteroid or Mars.
“We spent several years designing a miniature biomining reactor. And it’s basically a small piece of kit in which you put your pieces of rock, in our case basalt, and your dried microbes,” Cockle said.
The basalt rock they used in the experiment is similar to that found on the moon or Mars.
Italian astronaut Luca Parmitano placed the biomining reactor in a miniature centrifuge that rotated the samples around to simulate different gravitational conditions.
The microbes were then allowed to grow and feed for 21 days. The samples are then returned to Earth for analysis.
It’s called one of the bacterial species they tested Sphingomonas desiccabilis, and naturally lives in salt and rock crusts in deserts. Kokel said he had “successfully removed rare earth elements from the rock.”
“This direct result was very exciting because it was the first demonstration of extraterrestrial extraction.”
He said that what is even more interesting is how microbes manage to overcome the problem of different gravitational conditions – perhaps by changing their growth rate – to eventually reach the same concentration of bacterial cells under reduced gravity. as in terrestrial gravity.
“What our experiment suggests is that you can do biomining on asteroids or Mars, just like you can on Earth,” he said. “These different gravitational effects should not change our ability to perform biomining.”
A step towards self-sufficiency in space
Kokel said it envisions settlements on the moon or Mars, or asteroid bases, and there may be a giant processing facility nearby where microbes can be used to break up rocks to extract desired elements.
One problem with this technology, however, would be the potential bacterial contamination of places like Mars, where scientists are looking for signs of indigenous life.
“Obviously there is trade. And obviously you have to discuss whether you want to use biomines or other types of extraction,” said Kokel, who added that there is still a lot of research to be done before we get to this point.
He has another experiment called “BioAsteroid, “which is scheduled to fly in a few weeks, in which astronauts will conduct the same biomining experiment, but using a crushed meteorite instead of a rock similar to Mars.
Produced and written by Sonya Biting