Cyanobacteria are a group of photosynthetic bacteria, who use the energy of light to synthesize organic compounds from carbon dioxide, and producing oxygen this way.
Nostoc Commune is a species of cyanobacterium, common names include star jelly and fah-tsai. Its a colonial species, forming a gelatinous mass with other colonies growing nearby and its cells have no nucleus nor internal membrane system and between the ordinary cells nitrogen-fixing cells occur.
Nostoc Commune is found in many countries around the world and is able to survive in extreme conditions in polar regions and arid areas. The cells also contain pigments that absorb ultraviolet radiation, which enables it to survive in places where high levels of radiation occur.
Under adverse conditions, Nostoc Commune can remain dormant for an extended period of time and revive when conditions improve and water becomes available. The dessicated colony is resistant to heat and to repeated patterns of freezing and thawing and it has been found that extracellular polysaccharides are vital to its stress tolerance and ability to recover.
Like all microorganisms, Nostoc Commune needs the trace elements like K (potassium), Mg (magnesium), S (sulfur), P (phosphorus) and Fe (iron) to live so the rock or soil where it resides on will have to support it with those elements, although it can fix essential nitrogen from the atmosphere. Nitrogen was also found as a part of nitrate in sediments on Mars.
But the porosity of the surface of rocks may also play an important role in surviving the harsh conditions on Mars. Nostoc Commune forms a gelatinous mass or biofilm that could cover pores in rocks that may hold the produced oxygen and create a microhabitat this way. Also, the biofilm covering the surface of the rock will increase the possibility to collect deposited water vapour from the atmosphere.
Screenshots from images captured by the Perseverance rover on Sol 240 with the Mastcam-Z camera, examples of porous rock.
(Click on the images, and then again, for a closer view)
My question now is, what kind of rocks or soils on Mars will be best suited for Nostoc Commune to survive ?