Getting minerals into space can be a little easier than we thought – with the help of some of the earth’s smallest inhabitants.
International Space Station experiments show that bacteria can increase space mining efficiency by 400 percent, providing a much easier way to access materials we use widely in magnesium, iron, and rare-earth minerals such as electronics and alloys.
Here on earth, bacteria play a very important role in extracting minerals from the soil. They are involved in natural weather and rock breakdown, releasing the minerals they contain.
The ability of these bacteria to remove metals from their environment is used to aid in human mining operations; Called biomining, it has many benefits. For example, it can help reduce reliance on cyanide for gold mining. Bacteria can also help to deploy polluted soil.
In space environments like asteroids, the moon and Mars, mining will become a valuable tool as we set up human outposts. It is expensive to ferry material from the earth; Even the least expensive option is the price of SpaceX’s Falcon Heavy in the US. There is a payload of $ 1,500 per kilogram (2.2 pounds). So scientists are investigating the possibility of biomining in space.
Rosa Santomartino, an astrobiologist at the University of Edinburgh in the UK, explains, “Microorganisms are very versatile and can be used to complete a variety of processes as we move through space.” “Elemental mining is one of those possibilities.”
Over a period of 10 years, the team built a small, matchbox-sized device called a biomining reactor, which could be easily transported and installed on the International Space Station. Then, in July 2019, 18 of these biomining reactors were sent to the ISS for low-Earth orbit experiments.
(Kokel et al., Nature Communications, 2020)
Each biomining reactor contains a bacterial solution that sinks a small piece of basalt, a type of volcanic rock on the moon. For a period of three weeks, each reactor was exposed to a basalt bacterial solution to determine if the bacteria could perform the same rock-weather function in a low-gravity environment.
In simulated Mars gravity, simulated Earth gravity (using a centrifuge) and microgravity, the team experimented with different solutions for three different bacteria: Sphingomonas desiclabis, Bacillus subtilis And Capriavidus metalliderens. No bacteria-free control solution was used as baseline.
Researchers have found that there is no significant difference between bacterial leaching exposure based on gravitational conditions and B. subtilis And C. Metaliderens, The rare-earth mineral extraction was, respectively, less than the control solution and not significantly different.
However, this S. Decisable The solution resulted in the extraction of significantly more rare-earth minerals from basalt than the control solution.
For S. Decisable, In all the specific elements of the Earth and in the three gravitational conditions on the ISS, the organism leached 421.2 percent of the 111.9 percent non-biological control, ”the researchers wrote in their paper.
Since microgravity has previously been shown to influence microbial processes, the similarity between the concentrations of minerals in all three states of gravity was surprising. However, the team noted that all three bacteria have reached the same concentration in the state of gravity, probably because they have enough nutrients to do so.
They conclude that, with sufficient nutrients, a series of biomining is possible under conditions of gravity.
“Our experiments support the scientific and technological possibilities of mining biologically advanced elements in the solar system,” said Charles Cockle, an astrobiologist at the University of Edinburgh.
“While mining these elements in space and bringing them to Earth is not economically viable, biomining in space could potentially support the presence of self-sustaining humans in space.
“For example, our results suggest that the construction of robotic and human-oriented mines in the lunar Oceanic Procelarum region could be a fruitful direction of human scientific and economic development beyond Earth.”
Research has been published in Nature Communications.
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