Metals likely promoted protometabolism in early ocean alkaline hydrothermal systems
| Autor: | Ken Takai, Masahiro Yamamoto, Norio Kitadai, Ryuhei Nakamura, Yoshi Oono, Naohiro Yoshida |
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| Rok vydání: | 2019 |
| Předmět: |
Multidisciplinary
Standard hydrogen electrode Chemistry Hadean SciAdv r-articles Reductive tricarboxylic acid cycle Oceanography 010402 general chemistry 010502 geochemistry & geophysics 01 natural sciences Hydrothermal circulation 0104 chemical sciences Metal Geochemistry Abiogenesis visual_art Environmental chemistry visual_art.visual_art_medium Earth (chemistry) Research Articles Research Article 0105 earth and related environmental sciences Hydrothermal vent |
| Zdroj: | Science Advances |
| ISSN: | 2375-2548 |
| Popis: | Sulfide-to-metal electroreduction likely harnessed the reducing power of hydrothermal systems for the autotrophic origin of life. One of the most plausible scenarios of the origin of life assumes the preceding prebiotic autotrophic metabolism in sulfide-rich hydrothermal vent environments. However, geochemical mechanisms to harness the reductive power provided by hydrothermal systems remain to be elucidated. Here, we show that, under a geoelectrochemical condition realizable in the early ocean hydrothermal systems, several metal sulfides (FeS, Ag2S, CuS, and PbS) undergo hour- to day-scale conversion to the corresponding metals at ≤−0.7 V (versus the standard hydrogen electrode). The electrochemically produced FeS-Fe0 assemblage promoted various reactions including certain steps in the reductive tricarboxylic acid cycle with efficiencies far superior to those due to pure FeS. The threshold potential is readily generated in the H2-rich alkaline hydrothermal systems that were probably ubiquitous on the Hadean seafloor. Thus, widespread metal production and metal-sustained primordial metabolism were likely to occur as a natural consequence of the active hydrothermal processes on the Hadean Earth. |
| Databáze: | OpenAIRE |
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