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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Natural Radioactive Environments As Sources of Local Disequilibrium for the Emergence of Life

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Altair, Thiago [1, 2, 3] ; Sartori, Larissa M. [4] ; Rodrigues, Fabio [5] ; de Avellar, Marcio G. B. [6] ; Galante, Douglas [1, 2]
Total Authors: 5
[1] Univ Sao Paulo, Inst Fis Sao Carlos, Sao Carlos - Brazil
[2] Brazilian Ctr Res Energy & Mat CNPEM, Brazilian Synchrotron Light Lab LNLS, Av Giuseppe Maximo Scolfaro 10000, BR-13083100 Campinas, SP - Brazil
[3] Univ Sao Paulo, Inst Quim Sao Carlos, Sao Carlos - Brazil
[4] Univ Sao Paulo, Inst Matemat & Estat, Sao Paulo - Brazil
[5] Univ Sao Paulo, Inst Quim, Dept Quim Fundamental, Sao Paulo - Brazil
[6] Univ Fed Sao Paulo, Inst Ciencias Ambientais Quim & Farmaceut, Diadema - Brazil
Total Affiliations: 6
Document type: Journal article
Source: ASTROBIOLOGY; v. 20, n. 12 SEP 2020.
Web of Science Citations: 0

Certain subterranean environments of Earth have naturally accumulated long-lived radionuclides, such as(238)U,Th-232, and(40)K, near the presence of liquid water. In these natural radioactive environments, water radiolysis can produce chemical species of biological importance, such as H-2. Although the proposal of radioactive decay as an alternative source of energy for living systems has existed for >30 years, this hypothesis gained strength after the recent discovery of a peculiar ecosystem in a gold mine in South Africa, whose existence is dependent on chemical species produced by water radiolysis. In this study, we calculate the chemical disequilibrium generated locally by water radiolysis due to gamma radiation. We then analyze the possible contribution of this disequilibrium for the emergence of life, considering conditions of early Earth and having as reference the alkaline hydrothermal vent theory. Results from our kinetic model point out the similarities between the conditions caused by water radiolysis and those found on alkaline hydrothermal systems. Our model produces a steady increase of pH with time, which favors the formation of a natural electrochemical gradient and the precipitation of minerals with catalytic activity for protometabolism in this aqueous environment. We conclude by describing a possible free-energy conversion mechanism based on protometabolism, which could be a requisite for the emergence of life in Hadean Earth. (AU)

FAPESP's process: 16/08854-7 - Natural radioactive enviroments as sources of local chemical disequilibrium and its potencial prebiotic aftercomes
Grantee:Thiago Altair Ferreira
Support type: Scholarships in Brazil - Master
FAPESP's process: 16/06114-6 - The Neoproterozoic Earth System and the rise of biological complexity
Grantee:Ricardo Ivan Ferreira da Trindade
Support type: Research Projects - Thematic Grants