{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,27]],"date-time":"2026-09-27T17:27:57Z","timestamp":1790530077992,"version":"4.1.0"},"reference-count":36,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2019,2,1]],"date-time":"2019-02-01T00:00:00Z","timestamp":1548979200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100004410","name":"European Molecular Biology Organization","doi-asserted-by":"publisher","award":["ALTF 1455-2015"],"award-info":[{"award-number":["ALTF 1455-2015"]}],"id":[{"id":"10.13039\/100004410","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001691","name":"Japan Society for the Promotion of Science","doi-asserted-by":"publisher","award":["FY2016-PE-16721"],"award-info":[{"award-number":["FY2016-PE-16721"]}],"id":[{"id":"10.13039\/501100001691","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000001","name":"National Science Foundation","doi-asserted-by":"publisher","award":["1724300"],"award-info":[{"award-number":["1724300"]}],"id":[{"id":"10.13039\/100000001","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Life"],"abstract":"<jats:p>The alkaline-hydrothermal-vent theory for the origin of life predicts the spontaneous reduction of CO2, dissolved in acidic ocean waters, with H2 from the alkaline vent effluent. This reaction would be catalyzed by Fe(Ni)S clusters precipitated at the interface, which effectively separate the two fluids into an electrochemical cell. Using microfluidic reactors, we set out to test this concept. We produced thin, long Fe(Ni)S precipitates of less than 10 \u00b5m thickness. Mixing simplified analogs of the acidic-ocean and alkaline-vent fluids, we then tested for the reduction of CO2. We were unable to detect reduced carbon products under a number of conditions. As all of our reactions were performed at atmospheric pressure, the lack of reduced carbon products may simply be attributable to the low concentration of hydrogen in our system, suggesting that high-pressure reactors may be a necessity.<\/jats:p>","DOI":"10.3390\/life9010016","type":"journal-article","created":{"date-parts":[[2019,2,1]],"date-time":"2019-02-01T11:19:58Z","timestamp":1549019998000},"page":"16","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":28,"title":["Microfluidic Reactors for Carbon Fixation under Ambient-Pressure Alkaline-Hydrothermal-Vent Conditions"],"prefix":"10.3390","volume":"9","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5779-6543","authenticated-orcid":false,"given":"Victor","family":"Sojo","sequence":"first","affiliation":[{"name":"RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan"},{"name":"Systems Biophysics, Ludwig-Maximilian University of Munich, Munich 80799, Germany"},{"name":"Institute for Advanced Study, Berlin. Wallotstr. 19, Berlin 14193, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Aya","family":"Ohno","sequence":"additional","affiliation":[{"name":"RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shawn E.","family":"McGlynn","sequence":"additional","affiliation":[{"name":"RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan"},{"name":"Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550, Japan"},{"name":"Blue Marble Space Institute of Science, Seattle, WA 98154, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yoichi M.A.","family":"Yamada","sequence":"additional","affiliation":[{"name":"RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ryuhei","family":"Nakamura","sequence":"additional","affiliation":[{"name":"RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan"},{"name":"Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2019,2,1]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"207","DOI":"10.1016\/S0723-2020(88)80001-8","article-title":"Pyrite formation, the first energy source for life: A hypothesis","volume":"10","year":"1988","journal-title":"Syst. Appl. Microbiol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"238","DOI":"10.1111\/j.1365-3121.1989.tb00364.x","article-title":"In vitro growth of iron sulphide chimneys: Possible culture chambers for origin-of-life experiments","volume":"1","author":"Russell","year":"1989","journal-title":"Terra Nova"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"85","DOI":"10.1016\/0079-6107(92)90022-X","article-title":"Groundworks for an evolutionary biochemistry: The iron-sulphur world","volume":"58","year":"1992","journal-title":"Prog. Biophys. Mol. Biol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"337","DOI":"10.1016\/S0968-0004(00)89069-6","article-title":"No soup for starters? Autotrophy and the origins of metabolism","volume":"20","author":"Maden","year":"1995","journal-title":"Trends Biochem. Sci."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"358","DOI":"10.1016\/j.tibs.2004.05.007","article-title":"The rocky roots of the acetyl-CoA pathway","volume":"29","author":"Russell","year":"2004","journal-title":"Trends Biochem. Sci."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1887","DOI":"10.1098\/rstb.2006.1881","article-title":"On the origin of biochemistry at an alkaline hydrothermal vent","volume":"362","author":"Martin","year":"2007","journal-title":"Phil. Trans. R. Soc. London B"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1406","DOI":"10.1016\/j.cell.2012.11.050","article-title":"The origin of membrane bioenergetics","volume":"151","author":"Lane","year":"2012","journal-title":"Cell"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"181","DOI":"10.1089\/ast.2015.1406","article-title":"The origin of life in alkaline hydrothermal vents","volume":"16","author":"Sojo","year":"2016","journal-title":"Astrobiology"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"2857","DOI":"10.1098\/rstb.2011.0129","article-title":"Serpentinite and the dawn of life","volume":"366","author":"Sleep","year":"2011","journal-title":"Phil. Trans. R. Soc. London B. Biol. Sci."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"213","DOI":"10.1007\/s00239-014-9658-4","article-title":"An origin-of-life reactor to simulate alkaline hydrothermal vents","volume":"79","author":"Herschy","year":"2014","journal-title":"J. Mol. Evol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"12818","DOI":"10.1073\/pnas.0405289101","article-title":"H2-rich fluids from serpentinization: Geochemical and biotic implications","volume":"101","author":"Sleep","year":"2004","journal-title":"Proc. Natl. Acad. Sci."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"385","DOI":"10.1146\/annurev.earth.30.091201.141331","article-title":"Volcanoes, fluids, and life at mid-ocean ridge spreading centers","volume":"30","author":"Kelley","year":"2002","journal-title":"Annu. Rev. Earth Planet. Sci."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1428","DOI":"10.1126\/science.1102556","article-title":"A serpentinite-hosted ecosystem: The Lost City hydrothermal field","volume":"307","author":"Kelley","year":"2005","journal-title":"Science"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"156","DOI":"10.1096\/fasebj.5.2.1900793","article-title":"Life with CO or CO2 and H2 as a source of carbon and energy","volume":"5","author":"Wood","year":"1991","journal-title":"FASEB J."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"20120258","DOI":"10.1098\/rstb.2012.0258","article-title":"Beating the acetyl coenzyme A-pathway to the origin of life","volume":"368","author":"Nitschke","year":"2013","journal-title":"Phil. Trans. R. Soc. B."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"271","DOI":"10.1002\/bies.200900131","article-title":"How did LUCA make a living? Chemiosmosis in the origin of life","volume":"32","author":"Lane","year":"2010","journal-title":"BioEssays"},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Poehlein, A., Schmidt, S., Kaster, A.-K., Goenrich, M., Vollmers, J., Th\u00fcrmer, A., Bertsch, J., Schuchmann, K., Voigt, B., and Hecker, M. (2012). An ancient pathway combining carbon dioxide fixation with the generation and utilization of a sodium ion gradient for ATP synthesis. PLoS ONE, 7.","DOI":"10.1371\/journal.pone.0033439"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"609","DOI":"10.1042\/bj3500609","article-title":"Tetrahydrofolate and tetrahydromethanopterin compared: Functionally distinct carriers in C1 metabolism","volume":"350","author":"Maden","year":"2000","journal-title":"Biochem. J."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"311","DOI":"10.1016\/j.electacta.2014.07.078","article-title":"Electrochemical CO2 reduction by Ni-containing iron sulfides: How is CO2 electrochemically reduced at bisulfide-bearing deep-sea hydrothermal precipitates?","volume":"141","author":"Yamaguchi","year":"2014","journal-title":"Electrochim. Acta"},{"key":"ref_20","unstructured":"Lane, N. (2015). The Vital Question: Energy, Evolution, and the Origins of Complex Life, WW Norton & Company."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1","DOI":"10.3390\/life8040046","article-title":"Chemical diversity of metal sulfide minerals and its implications for the origin of life","volume":"8","author":"Li","year":"2018","journal-title":"Life"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"805","DOI":"10.1038\/nrmicro1991","article-title":"Hydrothermal vents and the origin of life","volume":"6","author":"Martin","year":"2008","journal-title":"Nat. Rev. Microbiol."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Sojo, V., Pomiankowski, A., and Lane, N. (2014). A bioenergetic basis for membrane divergence in archaea and bacteria. PLoS Biol., 12.","DOI":"10.1371\/journal.pbio.1001926"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"a015982","DOI":"10.1101\/cshperspect.a015982","article-title":"Bioenergetic constraints on the evolution of complex life","volume":"6","author":"Lane","year":"2014","journal-title":"Cold Spring Harb. Perspect. Biol."},{"key":"ref_25","first-page":"1","article-title":"Steep pH Gradients and Directed Colloid Transport in a Microfluidic Alkaline Hydrothermal Pore","volume":"56","author":"Kriegel","year":"2017","journal-title":"Angew. Chemie Int. Ed."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"17269","DOI":"10.1002\/chem.201503178","article-title":"Instantaneous click chemistry by a copper-containing polymeric-membrane-installed microflow catalytic reactor","volume":"21","author":"Yamada","year":"2015","journal-title":"Chem. A Eur. J."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"27045","DOI":"10.1021\/acs.jpcc.5b08813","article-title":"Growing inorganic membranes in microfluidic devices: Chemical gardens reduced to linear walls","volume":"119","author":"Batista","year":"2015","journal-title":"J. Phys. Chem. C"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1146","DOI":"10.1021\/ie50509a058","article-title":"Solubility of hydrogen, oxygen, nitrogen, and helium in water at elevated temperatures","volume":"44","author":"Pray","year":"1952","journal-title":"Ind. Eng. Chem."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"eaao7265","DOI":"10.1126\/sciadv.aao7265","article-title":"Geoelectrochemical CO production: Implications for the autotrophic origin of life","volume":"4","author":"Kitadai","year":"2018","journal-title":"Sci. Adv."},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Ooka, H., Mcglynn, S.E., and Nakamura, R. (2018). Electrochemistry at deep-sea hydrothermal vents: Utilization of the thermodynamic driving force towards the autotrophic origin of life. ChemElectroChem.","DOI":"10.1002\/celc.201801432"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1716","DOI":"10.1038\/s41559-017-0311-7","article-title":"Metals promote sequences of the reverse Krebs cycle","volume":"1","author":"Muchowska","year":"2017","journal-title":"Nat. Ecol. Evol."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1019","DOI":"10.1038\/s41559-018-0542-2","article-title":"Native iron reduces CO2 to intermediates and end-products of the acetyl-CoA pathway","volume":"2","author":"Varma","year":"2018","journal-title":"Nat. Ecol. Evol."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1007\/s00239-016-9756-6","article-title":"Natural pH gradients in hydrothermal alkali vents were unlikely to have played a role in the origin of life","volume":"83","author":"Jackson","year":"2016","journal-title":"J. Mol. Evol."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"75","DOI":"10.1007\/s00239-015-9727-3","article-title":"In praise of error","volume":"82","year":"2016","journal-title":"J. Mol. Evol."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"0012","DOI":"10.1038\/s41570-016-0012","article-title":"Studies on the origin of life\u2014the end of the beginning","volume":"1","author":"Sutherland","year":"2017","journal-title":"Nat. Rev. Chem."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1600217","DOI":"10.1002\/bies.201600217","article-title":"Proton gradients at the origin of life","volume":"39","author":"Lane","year":"2017","journal-title":"BioEssays"}],"container-title":["Life"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2075-1729\/9\/1\/16\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T12:30:26Z","timestamp":1760185826000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2075-1729\/9\/1\/16"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,2,1]]},"references-count":36,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2019,3]]}},"alternative-id":["life9010016"],"URL":"https:\/\/doi.org\/10.3390\/life9010016","relation":{},"ISSN":["2075-1729"],"issn-type":[{"value":"2075-1729","type":"electronic"}],"subject":[],"published":{"date-parts":[[2019,2,1]]}}}