Lichens have been shown to withstand very extreme conditions, including exposure to space and simulated Martian conditions (1). Trebouxiaceae microalgae are present in most known lichens that can be cultured in liquid or solid media. Trebouxiaceae can grow under very restrictive conditions of salt, dehydration, temperature or UV-light (2, 3,4) and are able to recover after long exposures to such conditions. We propose to check if its growth is feasible using in situ Martian resources (ISRU) supplemented with a minimum amount of human resources. We plan to simulate Mars conditions: low-pressure atmosphere rich in CO2, intense UV radiation, wide range of temperatures, absence of organic compounds on the surface (Martian regolith) and scarcity of water. We also propose the stable transformation of Trebouxiaceae, a tool that could lead to the production of biomass and specific products in small bioreactors. This research will help meet the challenge of long-term presence of humans in space, through environmental control and life-support technologies, as well as improve resource usage efficiency and reduce the consumables to be transported. Our goals are: a) to determine the most extreme combinations of physicochemical conditions that Trebouxiaceae can face and discover the molecular mechanisms that allow the survival of these organisms; b) to evaluate production of biomass, oxygen, and organic compounds under such conditions; c) the genetic transformation of Trebouxiaceae to implement production of substances of nutritional or environmental interest; and d) to examine the viability of these microorganisms on small-medium scale in bioreactors using ISRU for the production of food and the generation of a more favorable environment to life on Mars. The novelty of the idea resides in the use of lichen microalgae grown under Mars conditions and the development of solid bioreactors for the production of food and the generation of a more favorable environment to life on Mars.
