Department of Molecular Evolution, Centro de Astrobiología (CSIC-INTA), Carretera de Ajalvir km 4, Torrejón de Ardoz, 28850, Madrid, Spain.
Department of Planetology and Habitability, Centro de Astrobiología (CSIC-INTA), Carretera de Ajalvir km 4, Torrejón de Ardoz, 28850, Madrid, Spain.
Sci Rep. 2019 Feb 13;9(1):1916. doi: 10.1038/s41598-018-36579-7.
The conditions for the potential abiotic formation of organic compounds from inorganic precursors have great implications for our understanding of the origin of life on Earth and for its possible detection in other environments of the Solar System. It is known that aerosol-interfaces are effective at enhancing prebiotic chemical reactions, but the roles of salinity and pH have been poorly investigated to date. Here, we experimentally demonstrate the uniqueness of alkaline aerosols as prebiotic reactors that produce an undifferentiated accumulation of a variety of multi-carbon biomolecules resulting from high-energy processes (in our case, electrical discharges). Using simulation experiments, we demonstrate that the detection of important biomolecules in tholins increases when plausible and particular local planetary environmental conditions are simulated. A greater diversity in amino acids, carboxylic acids, N-heterocycles, and ketoacids, such as glyoxylic and pyruvic acid, was identified in tholins synthetized from reduced and neutral atmospheres in the presence of alkaline aqueous aerosols than that from the same atmospheres but using neutral or acidic aqueous aerosols.
无机前体潜在的非生物形成有机化合物的条件对我们理解地球上生命的起源以及在太阳系其他环境中可能的探测具有重要意义。众所周知,气溶胶界面在增强前生物化学反应方面非常有效,但迄今为止,盐度和 pH 值的作用还没有得到很好的研究。在这里,我们通过实验证明了碱性气溶胶作为前生物反应器的独特性,这种反应器能够产生多种多碳生物分子的无差别积累,这些分子是由高能过程(在我们的情况下是电放电)产生的。通过模拟实验,我们证明了当模拟到合理和特定的局部行星环境条件时,在 tholins 中检测到重要生物分子的可能性会增加。与使用中性或酸性气溶胶相比,在存在碱性水溶液气溶胶的情况下,从还原和中性大气中合成的 tholins 中鉴定出更多种类的氨基酸、羧酸、N-杂环和酮酸,如乙醛酸和丙酮酸。