Long-tcm1 space exploration colonization or habitation requires biological life support systems capable to cope with the deleterious space environment. The use of oxygenic photosynthetic microorganisms is an intriguing possibility mainly for food, O2 and nutraccutical compounds production. The critical points of utilizing plants-or algae-based life support systems arc the microgravity and iomizing radiation, which can influence the performance of these organisms. The aim of the present study was to assess the effects of space environment on the photosynthetic activity of various microorganisms and to select space stresstolerant strains. Photosystem 11 DI protein sitedirected and random mutants of the unicellular green alga Chlamydomonas reinhardtii were used as model system to test and select the amino acid substitutions capable to account for space tolerance. We focussed our studies also the accumulation of the Photosystem II photoprotective carotenoids (the xantophylls, violaxanthin. anteraxanthin and zeaxanthin), powerful antioxidants that epidemiological study demonstrated to be human vision protectors. For this purpose some mutants modified at the level of of enzymes involved in the biosynthesis of xanthophylls were included in the study [2] To identify the consequences of the space environment on the photosynthetic apparatus the changes in the Photosystem II efficiency were monitored in real time during the ESA-Russian FotonM3 mission in September 2007. For the space flight, a high-tech multicell fluorescence detector Photo-II was designed and built by the Centre for Advance Research in Space Optics in collaboration with Kayser-Italy. Bioscnsor and DAS. Photo-II is an automatic device developed to measure the chlorophyll fluorescence and to provide a living conditions for several different algae strains (Fig. I). Twelve different C. reinhardtii strains were analytically selected and two replications for each strain were brought to space. We analysed the hourly changes and the daily light dark trend in the maximum qumllum yield of PSII photochemistry, Fv/Fm (Fig.2). Some physiological parameters that characterize the post-flight effect on algae viability and photosynthetic performance were also determined. The dose and particle flux during Foton-M3 flight were monitorred in real time by the active spectrum-dosimeter LiulinPhoto, mounted on the top of Photo-II fluorimeter (Fig.2). Liulin-Photo measurements provided intonation on the amount of the energy released on the samples and the quality !lf the incident ionizing radiation [3]. The space flight results in relationship with the ground control simulation are discussed. [1] Johannigmeier et al. 2006. In Biotechnological Applications of Photosynthetic Proteins: Biochops, Bosensors ans Biodevices. Eds. M.T. Giardi , E.V.Piletska ISNB: 0-387-33009-4 [2] Nyogi et al 1997 Plant Cell 9. 1369-1380 [3] Damasso et al 2008 (in preparation)
Real-time monitoring of genetically modified Chlamydomonas reinhardtii during the Foton-M3 space mission.
Lambreva M;
2008
Abstract
Long-tcm1 space exploration colonization or habitation requires biological life support systems capable to cope with the deleterious space environment. The use of oxygenic photosynthetic microorganisms is an intriguing possibility mainly for food, O2 and nutraccutical compounds production. The critical points of utilizing plants-or algae-based life support systems arc the microgravity and iomizing radiation, which can influence the performance of these organisms. The aim of the present study was to assess the effects of space environment on the photosynthetic activity of various microorganisms and to select space stresstolerant strains. Photosystem 11 DI protein sitedirected and random mutants of the unicellular green alga Chlamydomonas reinhardtii were used as model system to test and select the amino acid substitutions capable to account for space tolerance. We focussed our studies also the accumulation of the Photosystem II photoprotective carotenoids (the xantophylls, violaxanthin. anteraxanthin and zeaxanthin), powerful antioxidants that epidemiological study demonstrated to be human vision protectors. For this purpose some mutants modified at the level of of enzymes involved in the biosynthesis of xanthophylls were included in the study [2] To identify the consequences of the space environment on the photosynthetic apparatus the changes in the Photosystem II efficiency were monitored in real time during the ESA-Russian FotonM3 mission in September 2007. For the space flight, a high-tech multicell fluorescence detector Photo-II was designed and built by the Centre for Advance Research in Space Optics in collaboration with Kayser-Italy. Bioscnsor and DAS. Photo-II is an automatic device developed to measure the chlorophyll fluorescence and to provide a living conditions for several different algae strains (Fig. I). Twelve different C. reinhardtii strains were analytically selected and two replications for each strain were brought to space. We analysed the hourly changes and the daily light dark trend in the maximum qumllum yield of PSII photochemistry, Fv/Fm (Fig.2). Some physiological parameters that characterize the post-flight effect on algae viability and photosynthetic performance were also determined. The dose and particle flux during Foton-M3 flight were monitorred in real time by the active spectrum-dosimeter LiulinPhoto, mounted on the top of Photo-II fluorimeter (Fig.2). Liulin-Photo measurements provided intonation on the amount of the energy released on the samples and the quality !lf the incident ionizing radiation [3]. The space flight results in relationship with the ground control simulation are discussed. [1] Johannigmeier et al. 2006. In Biotechnological Applications of Photosynthetic Proteins: Biochops, Bosensors ans Biodevices. Eds. M.T. Giardi , E.V.Piletska ISNB: 0-387-33009-4 [2] Nyogi et al 1997 Plant Cell 9. 1369-1380 [3] Damasso et al 2008 (in preparation)I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
