Image from Wikimedia Commons
The lack of life on Mars has remained a huge obstacle in the hopes for astronaut missions on Mars, but scientists have cultivated cyanobacteria that may change the way we look at potential life on the Red Planet. On February 16th, Researchers in Germany published a journal article describing the development of a new bioreactor capable of growing Anabaena cyanobacteria using only water, gases and nutrients available on Mars. Cyanobacteria is a microorganism that is related to bacteria and is capable of photosynthesis; they also are among the earlier life forms on Earth. This means that potentially astronauts would be able to use organisms that feed off of this bacteria and would be able to cultivate it with the naturally occurring resources on Mars. This would free up space on the spacecraft and also minimize cost and preparation time. However, the Martian atmosphere poses a major obstacle because it is extremely different from life on earth and this means the cyanobacteria must be tested for durability. Atmospheric pressure on Mars is less than 1% of Earth’s, this means that it is too low for liquid water to exist. Also the partial pressure of nitrogen gas—0.2 to 0.3 hPa—is too low for fixation. Due to this, the gears have shifted to trying not to recreate an earth-like, but martian atmosphere for the research towards supporting life on Mars. Cyanobacteria marks itself as an ideal candidate because of its ability for photosynthesis. Some cyanobacteria can even create nutrients from atmospheric nitrogen, a process called nitrogen fixation (when bacteria convert free nitrogen to ammonia). This would be extremely useful in ensuring a stable environment for the bacteria.
The efficiency of this idea will largely depend on cyanobacteria’s behavior under artificial atmospheres. To test the limits of it, the researchers at the University of Bremen in Germany have developed what is called the Atmos (Atmosphere Tester for Mars-bound Organic Systems). This machine can operate with the use of only resources available on Mars such as: nitrogen and CO2 from the atmosphere, water from ice, nutrients such as phosphorus, sulphur and calcium that are naturally occurring.
Image from Wikimedia Commons
In order to test the cyanobacteria’s capabilities the researchers used the Atmos system’s heated, pressure-controlled vessels with different ratios of CO2 and nitrogen, and different temperature and air pressure combinations. For the research and testing Anabaena sp. PCC 7938 was chosen because of its nitrogen fixing and photosynthesis abilities, and the fact that species related to Anabaena are edible, suitable for genetic engineering, and durable even in harsh conditions. The Anabaena was grown for “10 days in a mixture of 96% nitrogen and 4% carbon dioxide and at a pressure of 100 hPa—ten times lower than on Earth” (genengnews.com). It was also tried with a Mars substrate, and it also grew through a little slower than typical. Despite this, it is still a victory and holds huge potential for the future of space travel and understanding of Mars’ atmosphere as it develops in the years to come.