Life support system for space flights based on bacterial waste conversion

Regenerative life support system for long haul space flights based on bacterial waste conversion

For future long haul manned space missions (i.e. a lunar base or a mission to Mars), the life support systems in spacecraft have to become far more regenerative, including water gas and food generation from waste recycling.


MELiSSA (Micro-Ecological Life Support System Alternative) is a multidisciplinary project of the European Space Agency. It aims at the development of a bioregenerative life-support system to enable future long duration manned space missions (e.g. to Mars) by reconversion of organic gas, liquid and solid wastes into oxygen, water and food. Proper functioning of the MELiSSA loop will be dependent on the stability and axenicity of each of its compartments. Thus, it will be important to understand the microbiological phenomena encountered in MELiSSA due to reactor processing, long-time continuous culturing and external space conditions.

Several types of changed environmental conditions may be encountered by the MELiSSA bacteria. Therefore, the Laboratory for Molecular and Cellular Biology in SCK•CEN together with its academic partners is involved in the development of novel methods to detect metabolic/genomic instability, microbial contaminants and horizontal gene transfer in the MELiSSA loop.

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Reactor processing conditions (T°C, pH, light, influent medium composition of the previous reactor), external physical conditions (space ionizing radiation, microgravity, vibration, magnetism) and evolutionary processes might change the bacterial response. These responses could compromise the stability of the system. Therefore an understanding of the response to any possible environmental change is needed at the cellular, proteomic, transcriptomic and genomic level. The response of the MELiSSA organism Rhodospirillum rubrum to the space related environmental conditions of enhanced ionizing radiation and microgravity is investigated.

Bacteria, phages, virusses escaping from the first compartment could destabilize the next compartments, by accumulation, metabolic distrurbance, or by horizontal gene transfer. At SCK•CEN early warning systems are being developed to detect contaminating organisms, and to avoid propagation of a contamination into the system.

Because of its historically known nutritive and oxygen production properties, the cyanobacteria Arthrospira sp. (strain PCC 8005) has been selected as a food supplement and primary oxygen-producing organism in the MELiSSA loop. In order to assess the stability of its foodquality in space environmental conditions, the sequencing of its genome was undertaken. Further annotation and analysis of this genome is conducted at SCK•CEN with the help of its partners. Also the genomic plasticity of this strain under environmental stresses is under investigation.

With the consumption of pharmaceuticals and the use of personal care products, biologically active chemicals enter the MELiSSA loop. The fate of these compounds is currently unknown. If the contaminating chemical is recalcitrant, there is a danger that it could travel through the loop. Hence it can be directly reingested by the crew through plant and cyanobacteria consumption, thus leading to potential health hazards. As a consequence, the xenobiotic-degrading potential of the MELiSSA organisms and the effects of these compounds on the MELiSSA bacteria themselves is assessed. Due to the omnipresence and recalcitrance of the antibacterial agent triclosan, a major part of the researched is focused on the secondary effects of sublethal concentrations of Triclosan on the bacterium Rhodospirillum rubrum.

ESA video Natalie Leys  

The European Space Agency ESA published a video about life support systems for the International Space Station ISS and space exploration. In the video, our colleague Natalie Leys (Microbiology) explains how bacteria can be useful for water and waste management in future space missions. They examine this through flight experiments in the framework of the international MELiSSA project (Micro-Ecological Life Support System Alternative). 

>> Watch the video

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Projects & Partners

SCK•CEN participates in several Space Research projects in co-operation with various Belgian and European universities and industrial partners which are financially supported by the European Space Agency (ESA) as well as by the Belgian Federal Science Policy (Belspo) through following projects: MELGEN 1 & 2 – 'MELiSSA Genetic Stability Study 1 & 2 ' projects (GSTP, ….), Bellissima project (GSTP, ….),

Felice Mastroleo PreDoc project (SCK/CEN Fellowship, UMH, 2005-2008), Nicolas Morin PreDoc project (SCK•CEN Fellowship, ULg, 2006-2009), Benny Pycke PreDoc project (IWT Fellowship, UGent, 2006-2009)

In collaboration with: Mhr. C. Lasseur from ESA-ESTEC in The Netherlands, Prof. R. Wattiez from UMH in Belgium, Prof. A. Wilmotte from ULg in Belgium, Prof. N. Boon fom UGhent in Belgium, Dr. H. De Wever from Vito in Belgium, Génoscope in France, UAB in Spain, UBP in France, UoG in Canada, Institut Pasteur in France, INRA in France, CNRS in France