The potential role of extremophiles as food supplements in extraterrestrial bioscience engineering 

In Situ food production is being evaluated by space agencies to lead humans beyond Earth.This food production must be efficient, require as little energy as possible, and be simple toinitiate. The strategy considered multiple options, leveraging extraterrestrial in situ resources,the utilization of Bioregenerative Life Support Systems (BLSS), or a combination of thesemethods. In all cases, the provision of micronutrients from a mostly vegan diet does notcover the daily needs of astronauts, leading to deficiencies. In this work, the use of ediblemicroorganisms is evaluated to provide micronutrients lacking in current predominantlyvegan space diets. Numerous challenges exist in space conditions, necessitating the use ofmicroorganisms with robust DNA repair systems able to survive constant exposure to spaceradiation. As a result, radioresistant, osmotolerant, and acidophilic microorganisms, whichhave been listed for Qualified Presumption of Safety (QPS) or registered as Novel Food by theEuropean Food Safety Authority (EFSA), were selected. These extremophiles have thepotential to produce micronutrients absent from the current space diet. The selectedextremophiles will undergo testing in space conditions to assess their survival under ionizingradiation, reduced gravities, and utilizing in-situ resource techniques such as lysate fromcyanobacterium grown on Martian simulant. This work presents the results of a modeldeveloped to evaluate nutritional gaps in an exemplar space diet and explores the potentialof extremophiles to address these gaps. Results from the first screening show that theextremophilic non-conventional yeast Debaryomices hansenii can produce unsaturatedfatty acids and Ergosterol, which can be converted into Vitamin D2 by UV irradiation. Sporesof the halotolerant Bacillus subtilis have been studied for resistance to ionizing radiation andMartian surface conditions; it is widely studied for vitamin B2 production. Strains of theacidophilic Limosilactobacillus reuteri have been proven to produce Vitamin B12 and Folate.