title: Pressurized Martian-Like Pure CO2 Atmosphere Supports Strong Growth of Cyanobacteria, and Causes Significant Changes in their Metabolism.
abstract: Surviving of crews during future missions to Mars will depend on reliable and adequate supplies of essential life support materials, i.e. oxygen, food, clean water, and fuel. The most economical and sustainable (and in long term, the only viable) way to provide these supplies on Martian bases is via bio-regenerative systems, by using local resources to drive oxygenic photosynthesis. Selected cyanobacteria, grown in adequately protective containment could serve as pioneer species to produce life sustaining substrates for higher organisms. The very high (95.3 %) CO2 content in Martian atmosphere would provide an abundant carbon source for photo-assimilation, but nitrogen would be a strongly limiting substrate for bio-assimilation in this environment, and would need to be supplemented by nitrogen fertilizing. The very high supply of carbon, with rate-limiting supply of nitrogen strongly affects the growth and the metabolic pathways of the photosynthetic organisms. Here we show that modified, Martian-like atmospheric composition (nearly 100 % CO2) under various low pressure conditions (starting from 50 mbar to maintain liquid water, up to 200 mbars) supports strong cellular growth. Under high CO2 / low N2 ratio the filamentous cyanobacteria produce significant amount of H2 during light due to differentiation of high amount of heterocysts.
authors: Laboratory of Molecular Plant Biology, Department of Biochemistry, University of Turku, Turku, Finland.
authors: Gayathri
authors: G
authors: Murukesan
authors: Laboratory of Molecular Plant Biology, Department of Biochemistry, University of Turku, Turku, Finland.
authors: Hannu
authors: H
authors: Leino
authors: Laboratory of Molecular Plant Biology, Department of Biochemistry, University of Turku, Turku, Finland.
authors: Pirkko
authors: P
authors: Mäenpää
authors: Laboratory of Molecular Plant Biology, Department of Biochemistry, University of Turku, Turku, Finland.
authors: Kurt
authors: K
authors: Ståhle
authors: Centre of Integrated Bioscience for Animal Health and Alternative Energy, Faculty of Veterinary Technology, Kasetsart University, Bangkok, Thailand.
authors: Wuttinun
authors: W
authors: Raksajit
authors: Tuorla Observatory, Department of Physics and Astronomy, University of Turku, Piikkiö, Finland.
authors: Harry J
authors: HJ
authors: Lehto
authors: Laboratory of Molecular Plant Biology, Department of Biochemistry, University of Turku, Turku, Finland.
authors: Yagut
authors: Y
authors: Allahverdiyeva-Rinne
authors: Laboratory of Molecular Plant Biology, Department of Biochemistry, University of Turku, Turku, Finland. klehto@utu.fi.
authors: Kirsi
authors: K
authors: Lehto
mesh_terms: D017033:Anabaena / Q000254:growth & development* / Q000378:metabolism; D002245:Carbon Dioxide / Q000378:metabolism*; D018559:Exobiology; D006859:Hydrogen / Q000378:metabolism; D018535:Mars; D010313:Partial Pressure; D053545:Spirulina / Q000254:growth & development* / Q000378:metabolism; D046939:Synechocystis / Q000254:growth & development* / Q000378:metabolism
chemical_list: D002245:Carbon Dioxide; D006859:Hydrogen
keywords: Biohydrogen production; Biological life support systems; Effects of carbon/nitrogen ratio