Iron isotope fractionation during microbial reduction of iron: The importance of adsorption

Abstract

Research Article| March 01, 2004 Iron isotope fractionation during microbial reduction of iron: The importance of adsorption G.A. Icopini; G.A. Icopini 1Department of Geosciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA Search for other works by this author on: GSW Google Scholar A.D. Anbar; A.D. Anbar 2Department of Earth and Environmental Science and Department of Chemistry, University of Rochester, Rochester, New York 14627, USA Search for other works by this author on: GSW Google Scholar S.S. Ruebush; S.S. Ruebush 3 Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA Search for other works by this author on: GSW Google Scholar M. Tien; M. Tien 3 Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA Search for other works by this author on: GSW Google Scholar S.L. Brantley S.L. Brantley 4Department of Geosciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA Search for other works by this author on: GSW Google Scholar Author and Article Information G.A. Icopini 1Department of Geosciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA A.D. Anbar 2Department of Earth and Environmental Science and Department of Chemistry, University of Rochester, Rochester, New York 14627, USA S.S. Ruebush 3 Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA M. Tien 3 Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA S.L. Brantley 4Department of Geosciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA Publisher: Geological Society of America Received: 05 Sep 2003 Revision Received: 13 Nov 2003 Accepted: 18 Nov 2003 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2004) 32 (3): 205–208. https://doi.org/10.1130/G20184.1 Article history Received: 05 Sep 2003 Revision Received: 13 Nov 2003 Accepted: 18 Nov 2003 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation G.A. Icopini, A.D. Anbar, S.S. Ruebush, M. Tien, S.L. Brantley; Iron isotope fractionation during microbial reduction of iron: The importance of adsorption. Geology 2004;; 32 (3): 205–208. doi: https://doi.org/10.1130/G20184.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract In experiments investigating the causes of Fe isotope fractionation, the δ56/54Fe value of Fe(II) remaining in solution (Fe(II)(aq)) after reduction of Fe(III) (goethite) by Shewanella putrefaciens is ∼−1.2‰ relative to the goethite, in agreement with previous research. The addition of an electron shuttle did not affect fractionation, suggesting that Fe isotope fractionation may not be related to the kinetics of the electron transfer. Furthermore, in abiotic, anaerobic FeCl2(aq) experiments in which approximately one-third of Fe(II)(aq) is lost from solution due to adsorption of Fe(II) onto goethite, the δ56/54Fe value of Fe(II)(aq) remaining in solution is shifted by −0.8‰ relative to FeCl2. This finding demonstrates that anaerobic nonbiological interaction between Fe(II) and goethite can generate significant Fe isotope fractionation. Acid extraction of sorbed Fe(II) from goethite in experiments reveals that heavy Fe preferentially sorbs to goethite. Simple mass-balance modeling indicates that the isotopic composition of the sorbed Fe(II) pool is ∼+1.5‰ to +2.5‰ heavier than Fe in the goethite [∼2.7‰–3.7‰ heavier than aqueous Fe(II)]. Mass balance is also consistent with a pool of heavy Fe that is not released to solution during acid extraction. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.