DOI: 10.1111/gbi.12149
Scopus记录号: 2-s2.0-84951803239
论文题名: Patterns of sulfur isotope fractionation during microbial sulfate reduction
作者: Bradley A.S. ; Leavitt W.D. ; Schmidt M. ; Knoll A.H. ; Girguis P.R. ; Johnston D.T.
刊名: Geobiology
ISSN: 1472-4677
EISSN: 1472-4669
出版年: 2016
卷: 14, 期: 1 起始页码: 91
结束页码: 101
语种: 英语
Scopus关键词: Archean
; concentration (composition)
; environmental factor
; growth rate
; isotopic fractionation
; physiological response
; reduction
; sulfate-reducing bacterium
; sulfur
; Desulfovibrio alaskensis
; Desulfovibrio vulgaris
; sulfate
; sulfur
; Desulfovibrio
; growth, development and aging
; metabolism
; microbiology
; oxidation reduction reaction
; Desulfovibrio
; Environmental Microbiology
; Oxidation-Reduction
; Sulfates
; Sulfur Isotopes
Scopus学科分类: Earth and Planetary Sciences: General Earth and Planetary Sciences
; Environmental Science: General Environmental Science
; Agricultural and Biological Sciences: Ecology, Evolution, Behavior and Systematic
英文摘要: Studies of microbial sulfate reduction have suggested that the magnitude of sulfur isotope fractionation varies with sulfate concentration. Small apparent sulfur isotope fractionations preserved in Archean rocks have been interpreted as suggesting Archean sulfate concentrations of <200 μm, while larger fractionations thereafter have been interpreted to require higher concentrations. In this work, we demonstrate that fractionation imposed by sulfate reduction can be a function of concentration over a millimolar range, but that nature of this relationship depends on the organism studied. Two sulfate-reducing bacteria grown in continuous culture with sulfate concentrations ranging from 0.1 to 6 mm showed markedly different relationships between sulfate concentration and isotope fractionation. Desulfovibrio vulgaris str. Hildenborough showed a large and relatively constant isotope fractionation (34εSO4-H2S ≅ 25‰), while fractionation by Desulfovibrio alaskensis G20 strongly correlated with sulfate concentration over the same range. Both data sets can be modeled as Michaelis-Menten (MM)-type relationships but with very different MM constants, suggesting that the fractionations imposed by these organisms are highly dependent on strain-specific factors. These data reveal complexity in the sulfate concentration-fractionation relationship. Fractionation during MSR relates to sulfate concentration but also to strain-specific physiological parameters such as the affinity for sulfate and electron donors. Previous studies have suggested that the sulfate concentration-fractionation relationship is best described with a MM fit. We present a simple model in which the MM fit with sulfate concentration and hyperbolic fit with growth rate emerge from simple physiological assumptions. As both environmental and biological factors influence the fractionation recorded in geological samples, understanding their relationship is critical to interpreting the sulfur isotope record. As the uptake machinery for both sulfate and electrons has been subject to selective pressure over Earth history, its evolution may complicate efforts to uniquely reconstruct ambient sulfate concentrations from a single sulfur isotopic composition. Copyright © 2016 John Wiley & Sons Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/85120
Appears in Collections: 影响、适应和脆弱性
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作者单位: Department of Earth and Planetary Sciences, Washington University in St. Louis, St. Louis, MO, United States; Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA, United States; Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, United States; Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, United States
Recommended Citation:
Bradley A.S.,Leavitt W.D.,Schmidt M.,et al. Patterns of sulfur isotope fractionation during microbial sulfate reduction[J]. Geobiology,2016-01-01,14(1)