The protagonist Mark Watney rightly said in Martian language that our ambitions to establish a human base on the Red Planet would depend entirely on our “little science” skills. By taking up that challenge, researchers have successfully grown algae in a Mars-like style and paved the way for life support systems on Mars.
The choices of NASA and SpaceX make it clear that they plan to send people to Mars in the near future, yet the logical challenge of sustaining human life on our neighboring planet is huge. Transporting oxygen and food all the way from Earth would be illegal, so it is important to establish a way to produce these locally.
A class of microorganisms called cyanobacteria has long considered the best candidate for this purpose, as they produce oxygen through photosynthesis to convert gases such as nitrogen and carbon dioxide into nutrients that can sustain plant life. Mars contains both of these gases in its atmosphere, so scientists believe that cyanobacteria can used to manage living ecosystems on the surface of Mars.
However, since the atmospheric pressure on Mars is only a fraction of that of Earth, liquid water cannot exist and cyanobacteria are unable to grow. Creating bioreactors that mimic Earth’s atmospheric conditions could potentially solve this problem, yet rely on gases transferred from our home planet.
The authors of the study therefore sought to find out if cyanobacteria could grow using the only resources available on Mars, eliminating the need to transport materials from Earth.
Writing in the Frontiers Journal of Microbiology, they described the cultivation of a type of sorghum called Anabaena cyanobacteria in a specially designed bioreactor that they labeled as Atmos. Consisting of nine pressure-controlled chambers, Atoms allowed researchers to grow cyanobacteria in Mars-like conditions. Significantly, the species grows “vigorously” when cultivated in an atmosphere consisting of one-tenth of the Earth’s atmospheric pressure – 100 percent nitrogen and 96 percent carbon dioxide. Water was also included in the bioreactor, but it could found on Mars from large amounts of ice across parts of the planet.
In a statement, study author Cyprian Verseux explained, “cyanobacteria can use the low-cost gases in the Martian atmosphere as a source of their carbon and nitrogen,” adding “this could help sustain long-term missions to Mars.” As a next step, the researchers recreated the Martian regolith – a layer of dust on the planet’s surface – using it as their layer for growing cyanobacteria .
Again, algae have found to grow relatively successfully, although this is not enough compared to conventional growing medium. After 28 days, about half the amount of chlorophyll produced in regular soils produced in the same conditions as in the environment and in the specimens grown on Mars.
Finally, the researchers used Anabaena cyanobacteria as a substrate for the growth of E. coli bacteria. These organisms easily bioengineered and can used to make certain foods and medicines but will not grow on Mars. The results indicate that E. coli can caused by the dried Anabaena cyanobacteria that were produced under Martian conditions, indicating that the species may have contributed to the development of other cultures on Mars.
While all of this is quite exciting, he insisted that “our bioreactor, Atmos, is not the farming method we will use on Mars: it is to test the conditions we will provide on Earth.” “But our results will help guide the design of the Martian farming method.”