Likai Ariela, Papazi Aikaterini, Kotzabasis Kiriakos
Department of Biology, University of Crete, Voutes University Campus, GR-70013 Heraklion, Crete, Greece.
Life (Basel). 2025 Jan 17;15(1):117. doi: 10.3390/life15010117.
This study investigates the resilience of the unicellular green microalga to extreme atmospheric conditions simulating those of Mars, Jupiter, and Titan. Using Earth as a control, experiments were conducted under autotrophic and mixotrophic conditions to evaluate the organism's photosynthetic efficiency, oxygen production, and biomass growth over 2, 5, and 12 days. Photosynthetic performance was analyzed through chlorophyll a fluorescence induction (JIP-test), metabolic activity via gas chromatography, and biomass accumulation measurements. Despite the extreme atmospheric compositions-ranging from the CO-rich, low-pressure Martian atmosphere to the anoxic atmospheres of Jupiter and Titan- demonstrated resilience and a functional photosynthetic apparatus, maintaining growth and oxygen production. Notably, the Martian atmosphere enhanced photosynthetic performance, with fluorescence curves and Fv/Fm ratios surpassing Earth-like conditions, likely due to elevated CO and low pressure. Under mixotrophic conditions, the addition of glucose further enhanced metabolic activity and biomass growth across all atmospheres. These findings highlight the potential of for bioregenerative life support systems, enabling oxygen production, CO sequestration, and resource cultivation in extraterrestrial habitats. The study showcases the organism's adaptability to extreme environments, with implications for astrobiology, space exploration, and sustainable extraterrestrial ecosystems. These findings expand habitability criteria and explore extremophiles' potential to support life beyond Earth.
本研究调查了单细胞绿色微藻对模拟火星、木星和土卫六极端大气条件的耐受性。以地球作为对照，在自养和混合营养条件下进行实验，以评估该生物体在2天、5天和12天内的光合效率、氧气产生量和生物量增长。通过叶绿素a荧光诱导（JIP测试）分析光合性能，通过气相色谱分析代谢活性，并测量生物量积累。尽管大气成分极端——从富含一氧化碳的低压火星大气到木星和土卫六的缺氧大气——该微藻仍表现出耐受性和功能性光合装置，维持生长和氧气产生。值得注意的是，火星大气增强了光合性能，荧光曲线和Fv/Fm比值超过了类似地球的条件，这可能是由于一氧化碳含量升高和低压所致。在混合营养条件下，添加葡萄糖进一步增强了所有大气条件下的代谢活性和生物量增长。这些发现凸显了该微藻在生物再生生命支持系统中的潜力，能够在外星栖息地进行氧气产生、二氧化碳封存和资源培育。该研究展示了该生物体对极端环境的适应性，对天体生物学、太空探索和可持续外星生态系统具有重要意义。这些发现扩展了宜居性标准，并探索了极端微生物支持地球以外生命的潜力。
