DOI: 10.1111/gbi.12196
Scopus记录号: 2-s2.0-84978166283
论文题名: Molecular biosignatures reveal common benthic microbial sources of organic matter in ooids and grapestones from Pigeon Cay, The Bahamas
作者: O’Reilly S.S. ; Mariotti G. ; Winter A.R. ; Newman S.A. ; Matys E.D. ; McDermott F. ; Pruss S.B. ; Bosak T. ; Summons R.E. ; Klepac-Ceraj V.
刊名: Geobiology
ISSN: 1472-4677
EISSN: 1472-4669
出版年: 2017
卷: 15, 期: 1 起始页码: 112
结束页码: 130
语种: 英语
Scopus关键词: abundance
; bacterium
; benthic environment
; biodegradation
; biofilm
; carbonate
; community composition
; diatom
; fatty acid
; microbial community
; ooid
; organic matter
; sulfur cycle
; surf zone
; Bahamas
; Bacillariophyta
; Columba
; Proteobacteria
; lipid
; analysis
; Bahamas
; biofilm
; biota
; classification
; diatom
; isolation and purification
; microbiology
; Proteobacteria
; sediment
; Bahamas
; Biofilms
; Biota
; Diatoms
; Geologic Sediments
; Lipids
; Proteobacteria
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: Ooids are sedimentary grains that are distributed widely in the geologic record. Their formation is still actively debated, which limits our understanding of the significance and meaning of these grains in Earth’s history. Central questions include the role played by microbes in the formation of ooids and the sources of ubiquitous organic matter within ooid cortices. To address these issues, we investigated the microbial community composition and associated lipids in modern oolitic sands at Pigeon Cay on Cat Island, The Bahamas. Surface samples were taken along a transect from the shallow, turbulent surf zone to calmer, deeper water. Grains transitioned from shiny and abraded ooids in the surf zone, to biofilm-coated ooids at about 3 m water depth. Further offshore, grapestones (cemented aggregates of ooids) dominated. Benthic diatoms and Proteobacteria dominated biofilms. Taxa that may promote carbonate precipitation were abundant, particularly those associated with sulfur cycling. Compared to the lipids associated with surface biofilms, relict lipids bound within carbonate exhibited remarkably similar profiles in all grain types. The enhanced abundance of methyl-branched fatty acids and β-hydroxy fatty acids, 1-O-monoalkyl glycerol ethers and hopanoids bound within ooid and grapestone carbonate confirms a clear association of benthic sedimentary bacteria with these grains. Lipids bound within ooid cortices also contain molecular indicators of microbial heterotrophic degradation of organic matter, possibly in locally reducing conditions. These included the loss of labile unsaturated fatty acids, enhanced long-chain fatty acids/short-chain fatty acids, enriched stable carbon isotopes ratios of fatty acids, and very high stanol/stenol ratios. To what extent some of these molecular signals are derived from later heterotrophic endolithic activity remains to be fully resolved. We speculate that some ooid carbonate forms in microbial biofilms and that early diagenetic degradation of biofilms may also play a role in early stage carbonate precipitation around ooids. © 2016 John Wiley & Sons Ltd
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/85077
Appears in Collections: 影响、适应和脆弱性
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作者单位: Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, United States; School of Earth Sciences, University College Dublin, Dublin 4, Ireland; Department of Biological Sciences, Wellesley College, Wellesley, MA, United States; UCD Earth Institute, University College Dublin, Dublin 4, Ireland; Department of Geosciences, Smith College, Northampton, MA, United States; School of the Coast & Environment, Louisiana State University, Baton Rouge, LA, United States
Recommended Citation:
O’Reilly S.S.,Mariotti G.,Winter A.R.,et al. Molecular biosignatures reveal common benthic microbial sources of organic matter in ooids and grapestones from Pigeon Cay, The Bahamas[J]. Geobiology,2017-01-01,15(1)