Feb. 16 (UPI) -- Researchers in Germany have developed a new bioreactor capable of growing cyanobacteria using only water, gases and nutrients available on Mars.
The technology could pave the way for the kinds of sustainable biological life support systems that astronauts will need to produce their own food and oxygen on the Red Planet.
If and when astronauts are sent to Mars, there won't be room on the spaceship for lots of water, oxygen and food. Scientists will have to develop plans for producing essential consumables on the Martian surface -- using the resources that are already there.
Researchers described the breakthrough technology in a new paper, published Tuesday in the journal Frontiers in Microbiology.
"Here we show that cyanobacteria can use gases available in the Martian atmosphere, at a low total pressure, as their source of carbon and nitrogen," lead study author Cyprien Verseux said in a press release.
"Under these conditions, cyanobacteria kept their ability to grow in water containing only Mars-like dust and could still be used for feeding other microbes. This could help make long-term missions to Mars sustainable," said Verseux, an astrobiologist at the Center of Applied Space Technology and Microgravity at the University of Bremen.
Scientists have previously targeted cyanobacteria as a potential fuel source for biological life support systems.
Because the free-living bacteria performs photosynthesis, it could be used to produce oxygen -- the bacteria turn atmospheric nitrogen into usable nutrients.
Previous attempts to grow cyanobacteria at low pressures have failed, but creating Earth-like conditions on Mars would require too much energy.
To solve the problem, researchers developed the Atmos, or Atmosphere Tester for Mars-bound Organic Systems.
The machine is designed to operate using only inputs that are available on Mars: nitrogen and CO2 from the atmosphere, water mined from ice and nutrients found in Red Planet regolith, such as phosphorus, sulphur and calcium.
In the lab, researchers grew cyanobacteria in the Atmos system's nine heated, pressure-controlled vessels. Scientists tested different ratios of CO2 and nitrogen, as well as different temperature and air pressure combinations.
Because Martian regolith has yet to be collected and returned to Earth, scientists used a mixture designed to replicate Martian soil to provide the cyanobacteria cultures with proper nutrients.
For their experiments, scientists used a nitrogen-fixing cyanobacteria strain named Anabaena sp. PCC 7938, which previous studies suggested would be able to adapt to Martian conditions.
Inside the Atmos vessels, researchers were able to successfully grow cyanobacteria in a Mars-like regolith and a nitrogen- and carbon dioxide-rich atmosphere at low pressure.
Researchers are now working on ways to fine-tune their technology, as well as considering other cyanobacteria strains that could be used.
"We want to go from this proof-of-concept to a system that can be used on Mars efficiently," Verseux said. "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."
"For example, 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," Verseux said.
