36 research outputs found
Size-Dependent Affinity of Glycine and Its Short Oligomers to Pyrite Surface : A Model for Prebiotic Accumulation of Amino Acid Oligomers on a Mineral Surface
The interaction strength of progressively longer oligomers of glycine, (Gly), di-Gly, tri-Gly, and penta-Gly, with a natural pyrite surface was directly measured using the force mode of an atomic force microscope (AFM). In recent years, selective activation of abiotically formed amino acids on mineral surfaces, especially that of pyrite, has been proposed as an important step in many origins of life scenarios. To investigate such notions, we used AFM-based force measurements to probe possible non-covalent interactions between pyrite and amino acids, starting from the simplest amino acid, Gly. Although Gly itself interacted with the pyrite surface only weakly, progressively larger unbinding forces and binding frequencies were obtained using oligomers from di-Gly to penta-Gly. In addition to an expected increase of the configurational entropy and size-dependent van der Waals force, the increasing number of polar peptide bonds, among others, may be responsible for this observation. The effect of chain length was also investigated by performing similar experiments using L-lysine vs. poly-L-lysine (PLL), and L-glutamic acid vs. poly-L-glutamic acid. The results suggest that longer oligomers/polymers of amino acids can be preferentially adsorbed on pyrite surfaces
Amino Acids Generated from Hydrated Titan Tholins: Comparison with Miller-Urey Electric Discharge Products
Various analogues of Titan haze particles (termed tholins) have been made in the laboratory. In certain geologic environments on Titan, these haze particles may come into contact with aqueous ammonia (NH3) solutions, hydrolyzing them into molecules of astrobiological interest. A Titan tholin analogue hydrolyzed in aqueous NH3 at room temperature for 2.5 years was analyzed for amino acids using highly sensitive ultra-high performance liquid chromatography coupled with fluorescence detection and time-of-flight mass spectrometry (UHPLC-FDToF-MS) analysis after derivatization with a fluorescent tag. We compare here the amino acids produced from this reaction sequence with those generated from room temperature Miller-Urey (MU) type electric discharge reactions. We find that most of the amino acids detected in low temperature MU CH4N2H2O electric discharge reactions are generated in Titan simulation reactions, as well as in previous simulations of Triton chemistry. This argues that many processes provide very similar mixtures of amino acids, and possibly other types of organic compounds, in disparate environments, regardless of the order of hydration. Although it is unknown how life began, it is likely that given reducing conditions, similar materials were available throughout the early Solar System and throughout the universe to facilitate chemical evolution
Metabolomics As an Emerging Tool in the Search for Astrobiologically Relevant Biomarkers
It is now routinely possible to sequence and recover microbial genomes from environmental samples. To the degree it is feasible to assign transcriptional and translational functions to these genomes, it should be possible, in principle, to largely understand the complete molecular inputs and outputs of a microbial community. However, gene-based tools alone are presently insufficient to describe the full suite of chemical reactions and small molecules that compose a living cell. Metabolomic tools have developed quickly and now enable rapid detection and identification of small molecules within biological and environmental samples. The convergence of these technologies will soon facilitate the detection of novel enzymatic activities, novel organisms, and potentially extraterrestrial life-forms on solar system bodies. This review explores the methodological problems and scientific opportunities facing researchers who hope to apply metabolomic methods in astrobiology-related fields, and how present challenges might be overcome
Metabolomics as an emerging tool in the search for astrobiologically relevant biomarkers
© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Seyler, L., Kujawinski, E. B., Azua-Bustos, A., Lee, M. D., Marlow, J., Perl, S. M., & Cleaves, H. J. Metabolomics as an emerging tool in the search for astrobiologically relevant biomarkers. Astrobiology, (2020), doi:10.1089/ast.2019.2135.It is now routinely possible to sequence and recover microbial genomes from environmental samples. To the degree it is feasible to assign transcriptional and translational functions to these genomes, it should be possible, in principle, to largely understand the complete molecular inputs and outputs of a microbial community. However, gene-based tools alone are presently insufficient to describe the full suite of chemical reactions and small molecules that compose a living cell. Metabolomic tools have developed quickly and now enable rapid detection and identification of small molecules within biological and environmental samples. The convergence of these technologies will soon facilitate the detection of novel enzymatic activities, novel organisms, and potentially extraterrestrial life-forms on solar system bodies. This review explores the methodological problems and scientific opportunities facing researchers who hope to apply metabolomic methods in astrobiology-related fields, and how present challenges might be overcome.This study was partially supported by the ELSI Origins Network (EON), which is supported by a grant from the John Templeton Foundation. The opinions expressed in this publication are those of the authors and do not necessarily reflect the views of the John Templeton Foundation. This work was partially supported by a JSPS KAKENHI Grant-in-Aid for Scientific Research on Innovative Areas âHadean Bioscience,â grant number JP26106003, and also partially supported by Project âicyMARS,â funded by the European Research Council, ERC Starting Grant No. 307496. A.A-B thanks the contribution from the Project âMarsFirstWater,â funded by the European Research Council, ERC Consolidator Grant No. 818602 and the HFSP Project UVEnergy RGY0066/2018
Life-Detection Technologies for the Next Two Decades
Since its inception six decades ago, astrobiology has diversified immensely
to encompass several scientific questions including the origin and evolution of
Terran life, the organic chemical composition of extraterrestrial objects, and
the concept of habitability, among others. The detection of life beyond Earth
forms the main goal of astrobiology, and a significant one for space
exploration in general. This goal has galvanized and connected with other
critical areas of investigation such as the analysis of meteorites and early
Earth geological and biological systems, materials gathered by sample-return
space missions, laboratory and computer simulations of extraterrestrial and
early Earth environmental chemistry, astronomical remote sensing, and in-situ
space exploration missions. Lately, scattered efforts are being undertaken
towards the R&D of the novel and as-yet-space-unproven life-detection
technologies capable of obtaining unambiguous evidence of extraterrestrial
life, even if it is significantly different from Terran life. As the suite of
space-proven payloads improves in breadth and sensitivity, this is an apt time
to examine the progress and future of life-detection technologies.Comment: 6 pages, the white paper was submitted to and cited by the National
Academy of Sciences in support of the Astrobiology Science Strategy for the
Search for Life in the Univers
Deep Earth carbon reactions through time and space
The authors acknowledge partial support from the Sloan Foundation grant G-2016-7157.Reactions involving carbon in the deep Earth have limited manifestation on Earthâs surface, yet they have played a critical role in the evolution of our planet. The metal-silicate partitioning reaction promoted carbon capture during Earthâs accretion and may have sequestered substantial carbon in Earthâs core. The freezing reaction involving iron-carbon liquid could have contributed to the growth of Earthâs inner core and the geodynamo. The redox melting/freezing reaction largely controls the movement of carbon in the modern mantle, and reactions between carbonates and silicates in the deep mantle also promote carbon mobility. The ten-year activity of the Deep Carbon Observatory has made important contributions to our knowledge of how these reactions are involved in the cycling of carbon throughout our planet, both past and present, and helped to identify gaps in our understanding that motivate and give direction to future studies.Publisher PDFPeer reviewe
A Strategy for Origins of Life Research
Aworkshop was held August 26â28, 2015, by the Earth-
Life Science Institute (ELSI) Origins Network (EON,
see Appendix I) at the Tokyo Institute of Technology. This
meeting gathered a diverse group of around 40 scholars researching
the origins of life (OoL) from various perspectives
with the intent to find common ground, identify key questions
and investigations for progress, and guide EON by suggesting
a roadmap of activities.
Specific challenges that the attendees were encouraged to
address included the following: What key questions, ideas,
and investigations should the OoL research community address
in the near and long term? How can this community
better organize itself and prioritize its efforts? What roles
can particular subfields play, and what can ELSI and EON
do to facilitate research progress? (See also Appendix II.)
The present document is a product of that workshop; a
white paper that serves as a record of the discussion that
took place and a guide and stimulus to the solution of the
most urgent and important issues in the study of the OoL.
This paper is not intended to be comprehensive or a balanced
representation of the opinions of the entire OoL research
community. It is intended to present a number of
important position statements that contain many aspirational
goals and suggestions as to how progress can be made in
understanding the OoL.
The key role played in the field by current societies and
recurring meetings over the past many decades is fully acknowledged,
including the International Society for the
Study of the Origin of Life (ISSOL) and its official journal
Origins of Life and Evolution of Biospheres, as well as the
International Society for Artificial Life (ISAL)