Fractionation of Fe isotopes during Fe(II) oxidation by a marine photoferrotroph is controlled by the formation of organic Fe-complexes and colloidal Fe fractions

doi:10.1016/j.gca.2015.05.024

CORC > 地质与地球物理研究所 > 中国科学院地质与地球物理研究所 > 中国科学院地球与行星物理重点实验室

	Fractionation of Fe isotopes during Fe(II) oxidation by a marine photoferrotroph is controlled by the formation of organic Fe-complexes and colloidal Fe fractions
	Swanner, Elizabeth D.1; Wu, Wenfang 1,2; Schoenberg, Ronny 1; Byrne, James 1; Michel, F. Marc 3; Pan, Yongxin 2; Kappler, Andreas 1
刊名	GEOCHIMICA ET COSMOCHIMICA ACTA
	2015-09-15
卷号	165 页码:44-61
DOI	10.1016/j.gca.2015.05.024
文献子类	Article
英文摘要	Much interest exists in finding mineralogical, organic, morphological, or isotopic biosignatures for Fe(II)-oxidizing bacteria (FeOB) that are retained in Fe-rich sediments, which could indicate the activity of these organisms in Fe-rich seawater, more common in the Precambrian Era. To date, the effort to establish a clear Fe isotopic signature in Fe minerals produced by Fe(II)-oxidizing metabolisms has been thwarted by the large kinetic fractionation incurred as freshly oxidized aqueous Fe(III) rapidly precipitates as Fe(III) (oxyhydr) oxide minerals at near neutral pH. The Fe(III) (oxyhydr)oxide minerals resulting from abiotic Fe(II) oxidation are isotopically heavy compared to the Fe(II) precursor and are not clearly distinguishable from minerals formed by FeOB isotopically. However, in marine hydrothermal systems and Fe(II)-rich springs the minerals formed are often isotopically lighter than expected considering the fraction of Fe(II) that has been oxidized and experimentally-determined fractionation factors. We measured the Fe isotopic composition of aqueous Fe (Fe-aq) and the final Fe mineral (Fe-ppt) produced in batch experiment using the marine Fe(II)-oxidizing phototroph Rhodovulum iodosum. The delta Fe-56(aq) data are best described by a kinetic fractionation model, while the evolution of delta Fe-56(ppt) appears to be controlled by a separate fractionation process. We propose that soluble Fe(III), and Fe(II) and Fe(III) extracted from the Fe-ppt may act as intermediates between Fe(II) oxidation and Fe(III) precipitation. Based on Fe-57 Mossbauer spectroscopy, extended X-ray absorption fine structure (EXAFS) spectroscopy, and X-ray total scattering, we suggests these Fe phases, collectively Fe(II/III)(interm), may consist of organic-ligand bound, sorbed, and/or colloidal Fe(II) and Fe(III) mineral phases that are isotopically lighter than the final Fe(III) mineral product. Similar intermediate phases, formed in response to organic carbon produced by FeOB and inorganic ligands (e.g., SiO44- or PO43-), may form in many natural Fe(II)-oxidizing environments. We propose that the formation of these intermediates is likely to occur in organic-rich systems, and thus may have controlled the ultimate isotopic composition of Fe minerals in systems where Fe(II) was being oxidized by or in the presence of microbes in Earth's past. (C) 2015 Elsevier Ltd. All rights reserved.
WOS关键词	BANDED IRON FORMATIONS ; FE(II)-OXIDIZING PHOTOAUTOTROPHIC BACTERIA ; MOSSBAUER-SPECTROSCOPY ; OXIDIZING BACTERIA ; RHODOVULUM IODOSUM ; AQUEOUS FE(II) ; MICROBIAL MATS ; FERRIHYDRITE ; REDUCTION ; PRESERVATION
WOS研究方向	Geochemistry & Geophysics
语种	英语
WOS记录号	WOS:000358427700004
资助机构	U.S. DOE(DE-AC02-06CH11357) ; U.S. DOE(DE-AC02-06CH11357) ; National Science Foundation (NSF) International Research Fellowship(1064391) ; National Science Foundation (NSF) International Research Fellowship(1064391) ; CAS/SAFEA International Partnership Program for Creative Research Teams(KZCX2-YW-T10) ; CAS/SAFEA International Partnership Program for Creative Research Teams(KZCX2-YW-T10) ; NSFC(40821091) ; NSFC(40821091) ; German Research Foundation (DFG)(KA 1736/24-1) ; German Research Foundation (DFG)(KA 1736/24-1) ; European Research Council under the European Union's Seventh Framework Programme (FP)/ERC(307320) ; European Research Council under the European Union's Seventh Framework Programme (FP)/ERC(307320) ; U.S. DOE(DE-AC02-06CH11357) ; U.S. DOE(DE-AC02-06CH11357) ; National Science Foundation (NSF) International Research Fellowship(1064391) ; National Science Foundation (NSF) International Research Fellowship(1064391) ; CAS/SAFEA International Partnership Program for Creative Research Teams(KZCX2-YW-T10) ; CAS/SAFEA International Partnership Program for Creative Research Teams(KZCX2-YW-T10) ; NSFC(40821091) ; NSFC(40821091) ; German Research Foundation (DFG)(KA 1736/24-1) ; German Research Foundation (DFG)(KA 1736/24-1) ; European Research Council under the European Union's Seventh Framework Programme (FP)/ERC(307320) ; European Research Council under the European Union's Seventh Framework Programme (FP)/ERC(307320)
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/62302]
专题	地质与地球物理研究所_中国科学院地球与行星物理重点实验室
作者单位	1.Univ Tubingen, Dept Geosci, Tubingen, Germany 2.Chinese Acad Sci, Inst Geol & Geophys, Key Lab Earth & Planetary Phys, Beijing, Peoples R China 3.Virginia Tech, Dept Geosci, Blacksburg, VA USA
推荐引用方式 GB/T 7714	Swanner, Elizabeth D.,Wu, Wenfang,Schoenberg, Ronny,et al. Fractionation of Fe isotopes during Fe(II) oxidation by a marine photoferrotroph is controlled by the formation of organic Fe-complexes and colloidal Fe fractions[J]. GEOCHIMICA ET COSMOCHIMICA ACTA,2015,165:44-61.
APA	Swanner, Elizabeth D..,Wu, Wenfang.,Schoenberg, Ronny.,Byrne, James.,Michel, F. Marc.,...&Kappler, Andreas.(2015).Fractionation of Fe isotopes during Fe(II) oxidation by a marine photoferrotroph is controlled by the formation of organic Fe-complexes and colloidal Fe fractions.GEOCHIMICA ET COSMOCHIMICA ACTA,165,44-61.
MLA	Swanner, Elizabeth D.,et al."Fractionation of Fe isotopes during Fe(II) oxidation by a marine photoferrotroph is controlled by the formation of organic Fe-complexes and colloidal Fe fractions".GEOCHIMICA ET COSMOCHIMICA ACTA 165(2015):44-61.