Identified a suitable cyanobacterium to provide life support on Mars

Aug. 12 () –

A subspecies of cyanobacteria has been identified as apparently the most suitable for use in a biological life support system. that would allow humans to survive on Mars.

The results of an international research team, led by ZARM (Zentrum für angewandte Raumfahrttechnologie und Mikrogravitation) scientist Dr. Cyprien Verseux, are published in the journal Applied and Environmental Microbiology.

At first glance, the Red Planet’s inhospitable environment appears to contain few usable resources for a life support system or food production. But the carbon-rich atmosphere (95%), which contains nitrogen, and the red regolith soil, rich in iron and a host of other metals and minerals, are suitable for such bioprocesses, and the key is cyanobacteria.

While on Earth they often appear as annoying blue-green algae and spoil our summer bathing pleasure, in the context of Mars they can be described as masters of survival. Fed on Martian dust and atmosphere, and with the ability to photosynthesize, some microorganisms within this phylum could produce oxygen and form biomass, which could serve various purposes, including food production.

“When humans go to Mars, we will have to provide them with large amounts of consumables: food, water, oxygen and sometimes medicine. And if our presence there is to be sustainable, all of that cannot come from Earth, the costs and risks”. would be too high,” he said. it’s a statement Verseux, director of the Laboratory for Applied Space Microbiology at the Center for Applied Space Technology and Microgravity at the University of Bremen.

The approach of designing a life support system based on cyanobacteria is not new to space exploration research; however, progress in the field has been slowed by the lack of a shared model bacterium: the phylum Cyanobacteria numbers thousands of species. Cyprien Verseux and his colleagues have now identified the cyanobacterial strain Anabaena sp. PCC 7938 as very promising for a life support system on Mars.

Verseux explains how they arrived at the results: “We first shortlisted some strains of cyanobacteria based on the knowledge already available. We then searched for information on the genomic DNA of these strains and finally compared them through a series of experiments in the laboratory.”

“In short, we had two sets of criteria: the first concerned the abilities of cyanobacteria to feed on the resources available on Mars. The second concerned their abilities to support the growth of other organisms, such as edible plants and other bacteria. , which would be very valuable, but it couldn’t use Martian resources that directly.”

For this last point, the team succeeded, among other things, in cultivating duckweed as a nutrient-rich higher plant using extracts from the biomass of cyanobacteria. as the only raw material.

“This plant grows extremely fast and is completely edible, which makes it an excellent candidate for agriculture on Mars. As a fun fact, we actually isolated our duckweed from a stream in the Bremen landscape park,” said Tiago Ramalho. , also a scientist at ZARM and first author of the study.