Whole transcriptome analysis highlights nutrient limitation of nitrogen cycle bacteria in simulated microgravity

Tom Verbeelen, Celia Alvarez Hernandez, Thanh Huy Nguyen, Surya Gupta, Raf Aarts, Kevin Tabury, Baptiste Leroy, Ruddy Wattiez, Siegfried E. Vlaeminck, Natalie Leys, Ramon Ganigué, Felice Mastroleo

Research outputpeer-review


Regenerative life support systems (RLSS) will play a vital role in achieving self-sufficiency during long-distance space travel. Urine conversion into a liquid nitrate-based fertilizer is a key process in most RLSS. This study describes the effects of simulated microgravity (SMG) on Comamonas testosteroni, Nitrosomonas europaea, Nitrobacter winogradskyi and a tripartite culture of the three, in the context of nitrogen recovery for the Micro-Ecological Life Support System Alternative (MELiSSA). Rotary cell culture systems (RCCS) and random positioning machines (RPM) were used as SMG analogues. The transcriptional responses of the cultures were elucidated. For CO2-producing C. testosteroni and the tripartite culture, a PermaLifeTM PL-70 cell culture bag mounted on an in-house 3D-printed holder was applied to eliminate air bubble formation during SMG cultivation. Gene expression changes indicated that the fluid dynamics in SMG caused nutrient and O2 limitation. Genes involved in urea hydrolysis and nitrification were minimally affected, while denitrification-related gene expression was increased. The findings highlight potential challenges for nitrogen recovery in space.
Original languageEnglish
Article number3
Number of pages19
Journalnpj Microgravity
Issue number1
StatePublished - Dec 2024

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology (miscellaneous)
  • Agricultural and Biological Sciences (miscellaneous)
  • Medicine (miscellaneous)
  • Space and Planetary Science
  • Materials Science (miscellaneous)
  • Physics and Astronomy (miscellaneous)

Cite this