title: "SYMBIOSE" SYstem for Microgravity BIOregenerative Support of Experiments.
abstract: SYMBIOSE is an ESA supported research and development program which aims at establishing a first pilot model of a closed ecological system, compatible with operation in weightlessness conditions, and dedicated to scientific investigations in the microgravity environment. It integrates microalgal photosynthesis within an artificial ecosystem featuring a symbiotic strain of Chlorella (241 .80, Gottingen), which synthesizes and excretes substantial amounts of maltose, and is further looped on a consumer compartment. A technological concept has been developed. It is presently being integrated in order to gain knowledge on the system dynamics, and ultimately demonstrate the feasibility of such a biotechnology. Preliminary work on the photosynthetic metabolism of this microalga is being undertaken in order 1) to support later a mathematical formalisation of the dynamics of this artificial ecosystem, and, on this basis, 2) to compensate for its lack of stability with model-based external control. The most recent results are presented, along with a new design of the photobioreactor which integrates efficient light energy capture, microgravity compatible gas transfer and reduced shear stress.
authors.affiliation: European Space Agency, ESTEC, Noordwijk, The Netherlands.
authors.forename: F
authors.initials: F
authors.lastname: Brechignac
authors.forename: L
authors.initials: L
authors.lastname: Wolf
mesh_terms: D019149:Bioreactors; D002244:Carbon; D002245:Carbon Dioxide; D002708:Chlorella / Q000378:metabolism* / Q000502:physiology; D018504:Ecological Systems, Closed; D005060:Europe; D006863:Hydrogen-Ion Concentration; D007390:International Agencies; D008021:Life Support Systems / Q000295:instrumentation*; D008027:Light; D008320:Maltose / Q000096:biosynthesis; D009584:Nitrogen; D010100:Oxygen / Q000378:metabolism*; D010788:Photosynthesis / Q000502:physiology / Q000528:radiation effects; D010865:Pilot Projects; D013026:Space Flight / Q000295:instrumentation*; D013559:Symbiosis / Q000502:physiology; D018511:Systems Integration; D013696:Temperature; D014893:Weightlessness
chemical_list: D002245:Carbon Dioxide; D008320:Maltose; D002244:Carbon; D009584:Nitrogen; D010100:Oxygen