Scientists are developing bacteria that can be grown with only the local gases, water, and nutrients found on Mars, to make life on the Red Planet feasible.
All species of the bacteria anabaena cyanobacteria can be used to produce oxygen through photosynthesis, while others can turn atmospheric nitrogen into nutrients on Earth.
However, the challenge is that these bacteria cannot grow directly on Mars; the atmospheric pressure is less than one per cent of Earth’s, which is too low for liquid water, and the level of nitrogen gas is too low for the bacteria’s metabolism.
While terraforming Mars to recreate Earth’s atmosphere would take up valuable resources and costs, a bioreactor called Atmos (for “Atmosphere Tester for Mars-bound Organic Systems”) could be used to help the cyanobacteria grow.
Nitrogen and carbon dioxide are abundant in the Martian atmosphere, while water can be mined from ice on the planet. Nutrients, meanwhile, come from “regolith”, which is the dust that covers Mars and is rich in phosphorus, sulphur, and calcium.
In Atmos, the bacteria grew well under a substitute regolith material developed by the University of Central Florida called “Mars Global Simulant”, as well as under low-pressure conditions.
From this, scientists could use the bacteria to grow E. coli, which could then be used to produce food and medicine on Mars that other bacteria could not.
“Our bioreactor, Atmos, is not the cultivation system we would use on Mars: it is meant to test, on Earth, the conditions we would provide there. But our results will help guide the design of a Martian cultivation system”, Dr Cyprien Verseux, an astrobiologist who heads the Laboratory of Applied Space Microbiology at the Center of Applied Space Technology and Microgravity (ZARM) of the University of Bremen, explained.
“The lower pressure means that we can develop a more lightweight structure that is more easily freighted, as it won’t have to withstand great differences between inside and outside,” he added. The research has been published in Frontiers in Microbiology.