Viva Origino
Online ISSN : 1346-6933
Print ISSN : 0910-4003
46 巻, 2 号
特集 生命の起原および進化学会の第43回学術講演 シンポジウムより
  • 大野 宗祐
    2018 年 46 巻 2 号 p. 2-
    発行日: 2018年
    公開日: 2021/11/16
    ジャーナル フリー

      Determining the location of the “biopause” (i.e., the upper boundary of the biosphere of the Earth) and the biological flux across the biopause are the key to our understanding of the universality, distribution, origin, and evolution of life in the universe. It is widely accepted that the tropospheric atmosphere contains bioaerosol, although the flux of microbes from the troposphere to the stratosphere is small and dynamical and biological lifetime in the stratosphere are short. However, the presence of microbes in the stratosphere has been recorded in previous experiments using balloons, aircraft, and rockets. The most direct information available that can be used to investigate the biopause is the distribution and dynamicity of life in the middle atmosphere.

      In this paper, we introduce the outline and the initial results of the Biopause project, which is the first observational study of stratospheric bioaerosols to include nonculturable species and to successfully constrain their number density. The initial results from the first balloon experiment of the Biopause project represent an important step towards the planning of future experiments that will improve our understanding of stratospheric life and assist with the identification and characterization of the biopause.

  • 北台 紀夫
    2018 年 46 巻 2 号 p. 3-
    発行日: 2018年
    公開日: 2021/11/16
    ジャーナル フリー

    Amino acids are life’s essential building blocks on Earth, and possibly are in Universe. However, what environmental conditions favor their abiotic polymerization remains poorly understood. Here I introduce a thermodynamic predictive model for amino acid polymerization on mineral surfaces using L-lysine–silica combination [1] as an example. This methodology enables calculation of the monomer–polymer equilibria of amino acids in the presence of minerals as a function of various environmental parameters (e.g., pH, ionic strength, amino acid concentration, and solid/water ratio). Future experimental characterizations of amino acid–mineral interactions and thermodynamic prediction using thereby obtained datasets will provide a quantitative insight into geochemical settings favorable for the generation and elongation of peptides and their sustained life’s origin on Earth and other Earth-type planets.