title: Experimental design and environmental parameters affect Rhodospirillum rubrum S1H response to space flight.
abstract: In view of long-haul space exploration missions, the European Space Agency initiated the Micro-Ecological Life Support System Alternative (MELiSSA) project targeting the total recycling of organic waste produced by the astronauts into oxygen, water and food using a loop of bacterial and higher plant bioreactors. In that purpose, the alpha-proteobacterium, Rhodospirillum rubrum S1H, was sent twice to the International Space Station and was analyzed post-flight using a newly developed R. rubrum whole genome oligonucleotide microarray and high throughput gel-free proteomics with Isotope-Coded Protein Label technology. Moreover, in an effort to identify a specific response of R. rubrum S1H to space flight, simulation of microgravity and space-ionizing radiation were performed on Earth under identical culture set-up and growth conditions as encountered during the actual space journeys. Transcriptomic and proteomic data were integrated and permitted to put forward the importance of medium composition and culture set-up on the response of the bacterium to space flight-related environmental conditions. In addition, we showed for the first time that a low dose of ionizing radiation (2 mGy) can induce a significant response at the transcriptomic level, although no change in cell viability and only a few significant differentially expressed proteins were observed. From the MELiSSA perspective, we could argue the effect of microgravity to be minimized, whereas R. rubrum S1H could be more sensitive to ionizing radiation during long-term space exploration mission.
authors: Expert Group Molecular and Cellular Biology, Belgian Nuclear Research Center (SCK.CEN), Mol, Belgium.
authors: Felice
authors: F
authors: Mastroleo
authors: Rob
authors: R
authors: Van Houdt
authors: Baptiste
authors: B
authors: Leroy
authors: M Abderrafi
authors: MA
authors: Benotmane
authors: Ann
authors: A
authors: Janssen
authors: Max
authors: M
authors: Mergeay
authors: Filip
authors: F
authors: Vanhavere
authors: Larissa
authors: L
authors: Hendrickx
authors: Ruddy
authors: R
authors: Wattiez
authors: Natalie
authors: N
authors: Leys
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D020411:Oligonucleotide Array Sequence Analysis; D020543:Proteome / Q000032:analysis; D011839:Radiation, Ionizing; D012247:Rhodospirillum rubrum / Q000737:chemistry / Q000235:genetics / Q000502:physiology* / Q000528:radiation effects; D013026:Space Flight; D013312:Stress, Physiological; D014893:Weightlessness
chemical_list: D001426:Bacterial Proteins; D020543:Proteome