Bacteria could mine the metals in space

If giant structures to excavate extraterrestrial soil are still science fiction scenarios, space mining is already a reality in small structures the size of a matchbox aboard the International Space Station (ISS) – and of course the miners are not. . humans but rather bacteria.

The 18 prototypes for the so-called biomineration took place in July of last year. The RioRock project, by astrobiologists from the University of Edinburgh in the UK, aimed to reveal how low gravity affects the natural ability of bacteria to extract useful materials from rocks.

In each biomineral reactor, small pieces of basalt rock were immersed in solutions containing cultures of the bacteria Sphingomonas desiccabilis, Bacillus subtilis, and Cupriavidus metallidurans (plus a bacterial-free solution for control). For three weeks, the scientists observed whether the bacteria would behave like on Earth, but under the simulated gravity of the Moon and Mars.

When they reproduce, bacteria create biofilms, communities of cells that adhere to a surface and to each other and are protected by a slime. When it forms, it is so cohesive and adherent to the surface it has spawned on that it is almost impossible to stop its expansion. ]

It was already known that low or no gravity affects the adhesion of bacteria to surfaces (if they cannot adhere to the rock and cover it, they do not digest it). With the information obtained it will be possible to control the process on Earth.

Fertile desolate worlds

The experiment revealed that bacteria can increase the extraction of rare earth metals (from the technology industry) from basalt by up to 400%.

These bacteria may also be the key to transforming the surfaces of desolate worlds into fertile land. According to astrophysicist Charles Cockell, “robotic mines in the region of the Moon Oceanus Procellarum, which has rare earth metal rocks, would represent human scientific and economic advance beyond Earth.”

The next experiment on the ISS will be BioAsteroid; similar to BioRock, it will use as a base not basalt, but material collected from asteroids.