Growth of terrestrial cyanobacterium, Nostoc sp., on Martian Regolith Simulant and its vacuum tolerance

Abstract

The growth of terrestrial cyanobacterium, Nostoc sp., on the Martian Regolith Simulant (MRS) and its vacuum tolerance were studied as one of our challenges in this century to inhabit Mars. The viability of the tested cyanobacteria was evaluated by microscopic observation after staining by fluorescein diacetate (FDA). The general terrestrial cyanobacterial lump collected from the ground showed a significantly high tolerance to a high vacuum environment (10-5 Pa) for over one year. To scientifically elucidate its high tolerance function, Nostoc sp. HK-01 was used as another suitable scientific material for this study. After exposure to the high vacuum environment (10-5 Pa) for two weeks, Nostoc sp. HK-01 began to grow again. Some of it was also re-incubated again with a liquid culture medium. The A'MED (Arai's Mars Ecosystem Dome) is designed to be installed on Mars for agricultural production. A'MED was useful to conduct our study. We performed the fundamental experiment using the MRS. Nostoc sp. HK-01 was found to grow for over 140 days along with having the normal function of chlorophyll synthesis on the MRS. These results show the possibility that cyanobacteria could adapt to the MRS, and grow under the low pressure environment expected on Mars.