Fe isotope fractionation during Fe(II) oxidation by the marine photoferrotroph Rhodovulum iodosum in the presence of Si - Implications for Precambrian iron formation deposition

doi:10.1016/j.gca.2017.05.033

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

	Fe isotope fractionation during Fe(II) oxidation by the marine photoferrotroph Rhodovulum iodosum in the presence of Si - Implications for Precambrian iron formation deposition
	Wu, Wenfang 1,4; Swanner, Elizabeth D.2; Kleinhanns, Ilka C.3; Schoenberg, Ronny 3; Pan, Yongxin 4; Kappler, Andreas 1,5
刊名	GEOCHIMICA ET COSMOCHIMICA ACTA
	2017-08-15
卷号	211 页码:307-321
关键词	Banded iron formations Precambrian ocean Phototrophic iron oxidation Bacteria Iron isotopes Silica
ISSN号	0016-7037
DOI	10.1016/j.gca.2017.05.033
文献子类	Article
英文摘要	The iron (Fe) isotopic composition of Precambrian iron formations (IFs), besides providing geological context through its mineralogical properties, was suggested to function as a biosignature that can be used to infer a potential microbial role in the formation of the deposited Fe minerals. Anoxygenic phototrophic Fe(II)-oxidizing bacteria (photoferrotrophs), capable of oxidizing Fe(II) anoxically using light energy, were potentially involved in Fe(II) oxidation in anoxic or suboxic Precambrian oceans. The effect of Si on Fe isotopic fractionation between aqueous Fe(II) and Fe-Si-co-precipitates has been investigated before. However, it is currently unknown how stable Fe isotopes are fractionated during enzymatic Fe(II) oxidation under marine hydrogeochemical conditions, and particularly how the presence of Si affects the Fe isotope composition and the isotopic exchange among different Fe phases. We therefore studied Fe isotope fractionation during Fe(II) oxidation by the marine photo-ferrotroph Rhodovulum iodosum in simulated Precambrian seawater amended with 1 mMdissolved Si. Our results show that the change in the Fe isotope compositions over time for both the initial aqueous Fe(II) (Fe-aq) and the Fe(III) precipitates (Fe-ppt) follow a Rayleigh distillation model. Moreover, the fractionation (delta(56) Feppt-aq) determined independently from either d56 Feaq or delta(56) Fe-ppt data resulted in a value of 2.3 perpendicular to 0.3 (2SD, N = 6). This value differs from the fractionation factor determined previously for Fe(II) oxidation by R. iodosum in the absence of Si, where the fractionation calculated from delta(56) Fe-aq (i.e. 0.96-1.18) was different from that calculated from delta(56) Fe-ppt (1.96-1.98). This difference was attributed to isotopic exchange processes with soluble and sorbed Fe species. The present study suggests that Si present in Precambrian oceans retards Fe isotopic exchange, likely through combined effects of complexation of dissolved Fe species by Si and sorption of Si to Fe(III) minerals, thus lowering sorption of Fe(II) to the Fe(III) minerals, which is necessary for isotopic exchange. In summary our data suggests that Si in ancient oceans played a key role for the Fe isotope composition of Fe(III) minerals that were deposited by photoferrotrophic iron oxidation in Precambrian oceans by minimizing subsequent isotope exchange and recrystallization processes with aqueous Fe(II). (C) 2017 Elsevier Ltd. All rights reserved.
WOS关键词	FE(II)-OXIDIZING PHOTOAUTOTROPHIC BACTERIA ; SIMULATED ARCHEAN SEAWATER ; MID-ATLANTIC RIDGE ; MICROBIAL REDUCTION ; OXIDE REDUCTION ; AQUEOUS FE(II) ; FERROUS-IRON ; ANCIENT ENVIRONMENTS ; CRYSTAL-CHEMISTRY ; FORMATION GENESIS
WOS研究方向	Geochemistry & Geophysics
语种	英语
出版者	PERGAMON-ELSEVIER SCIENCE LTD
WOS记录号	WOS:000405786800017
资助机构	NSFC(41502320) ; CSC-DAAD postdoc scholarship ; China Postdoc Science Foundation(2014M560115) ; European Research Council (ERC)(307320-MICROFOX) ; DFG(KA 1736/27-1) ; NSFC(41502320) ; CSC-DAAD postdoc scholarship ; China Postdoc Science Foundation(2014M560115) ; European Research Council (ERC)(307320-MICROFOX) ; DFG(KA 1736/27-1) ; NSFC(41502320) ; CSC-DAAD postdoc scholarship ; China Postdoc Science Foundation(2014M560115) ; European Research Council (ERC)(307320-MICROFOX) ; DFG(KA 1736/27-1) ; NSFC(41502320) ; CSC-DAAD postdoc scholarship ; China Postdoc Science Foundation(2014M560115) ; European Research Council (ERC)(307320-MICROFOX) ; DFG(KA 1736/27-1)
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/43596]
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
通讯作者	Kappler, Andreas
作者单位	1.Univ Tubingen, Ctr Appl Geosci, Geomicrobiol, Sigwartstr 10, D-72076 Tubingen, Germany 2.Iowa State Univ, Dept Geol & Atmospher Sci, Ames, IA USA 3.Univ Tubingen, Dept Geosci, Isotope Geochem, Tubingen, Germany 4.Chinese Acad Sci, Inst Geol & Geophys, Key Lab Earths Deep Interior, Beijing, Peoples R China 5.Aarhus Univ, Dept Biosci, Ctr Geomicrobiol, Aarhus, Denmark
推荐引用方式 GB/T 7714	Wu, Wenfang,Swanner, Elizabeth D.,Kleinhanns, Ilka C.,et al. Fe isotope fractionation during Fe(II) oxidation by the marine photoferrotroph Rhodovulum iodosum in the presence of Si - Implications for Precambrian iron formation deposition[J]. GEOCHIMICA ET COSMOCHIMICA ACTA,2017,211:307-321.
APA	Wu, Wenfang,Swanner, Elizabeth D.,Kleinhanns, Ilka C.,Schoenberg, Ronny,Pan, Yongxin,&Kappler, Andreas.(2017).Fe isotope fractionation during Fe(II) oxidation by the marine photoferrotroph Rhodovulum iodosum in the presence of Si - Implications for Precambrian iron formation deposition.GEOCHIMICA ET COSMOCHIMICA ACTA,211,307-321.
MLA	Wu, Wenfang,et al."Fe isotope fractionation during Fe(II) oxidation by the marine photoferrotroph Rhodovulum iodosum in the presence of Si - Implications for Precambrian iron formation deposition".GEOCHIMICA ET COSMOCHIMICA ACTA 211(2017):307-321.