Print Email Facebook Twitter Nitrogen cycle microorganisms can be reactivated after Space exposure Title Nitrogen cycle microorganisms can be reactivated after Space exposure Author Lindeboom, R.E.F. (TU Delft Sanitary Engineering; Universiteit Gent) Ilgrande, Chiara (Universiteit Gent) Carvajal-Arroyo, José M. (Universiteit Gent) Clauwaert, Peter (Universiteit Gent) Date 2018 Abstract Long-term human Space missions depend on regenerative life support systems (RLSS) to produce food, water and oxygen from waste and metabolic products. Microbial biotechnology is efficient for nitrogen conversion, with nitrate or nitrogen gas as desirable products. A prerequisite to bioreactor operation in Space is the feasibility to reactivate cells exposed to microgravity and radiation. In this study, microorganisms capable of essential nitrogen cycle conversions were sent on a 44-days FOTON-M4 flight to Low Earth Orbit (LEO) and exposed to 10−3–10−4 g (gravitational constant) and 687 ± 170 µGy (Gray) d−1 (20 ± 4 °C), about the double of the radiation prevailing in the International Space Station (ISS). After return to Earth, axenic cultures, defined and reactor communities of ureolytic bacteria, ammonia oxidizing archaea and bacteria, nitrite oxidizing bacteria, denitrifiers and anammox bacteria could all be reactivated. Space exposure generally yielded similar or even higher nitrogen conversion rates as terrestrial preservation at a similar temperature, while terrestrial storage at 4 °C mostly resulted in the highest rates. Refrigerated Space exposure is proposed as a strategy to maximize the reactivation potential. For the first time, the combined potential of ureolysis, nitritation, nitratation, denitrification (nitrate reducing activity) and anammox is demonstrated as key enabler for resource recovery in human Space exploration. To reference this document use: http://resolver.tudelft.nl/uuid:d24a6d16-9963-4f9d-ac93-5e810953da48 DOI https://doi.org/10.1038/s41598-018-32055-4 ISSN 2045-2322 Source Scientific Reports, 8 (1) Part of collection Institutional Repository Document type journal article Rights © 2018 R.E.F. Lindeboom, Chiara Ilgrande, José M. Carvajal-Arroyo, Peter Clauwaert, More Authors Files PDF s41598_018_32055_4.pdf 1.61 MB Close viewer /islandora/object/uuid:d24a6d16-9963-4f9d-ac93-5e810953da48/datastream/OBJ/view