Feasibility as feedstock of the cyanobacterium Chroococcidiopsis sp. 029 cultivated with urine-supplemented moon and mars regolith simulants

Abstract

Biology-driven in situ resource utilization (bio-ISRU) should provide a breakthrough in supporting long-term human permanence on the Moon and Mars that will rely on the ability to produce consumables on site. Lithotrophic cyanobacteria are gaining interest for linking ISRU to life-support systems: In the “PowerCell” concept, cyanobacteria are grown with raw materials available on the Moon and Mars and used to feed bacteria producing consumables. Here we showed that lunar and martian regolith simulants as well as water-released minerals (supplemented with a nitrogen source) can support planktonic and biofilm growth of the desert cyanobacterium Chroococcidiopsis sp. 029. Such a growth versality is relevant to meet different technological requirements of future cultivation hardware to be used on the Moon (and eventually on Mars). We showed that this cyanobacterium can use urea as a nitrogen source and be cultivated with lunar and martian regolith simulants supplemented with synthetic human urine. Notably, the biomass yielded from each experimental set up could be used as feedstock for bacteria. Results provided a proof-of-concept of the feasibility of Chroococcidiopsis grown with raw materials available on site on the Moon and Mars and human waste, to “power” bio-production by feeding bacteria useful for bioprocesses to support human settlements beyond Earth.