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Method for Assessing Mineral Composition-Dependent Patterns in Microbial Diversity Using Magnetic and Density Separation

Harrison, Benjamin K. and Orphan, Victoria J. (2012) Method for Assessing Mineral Composition-Dependent Patterns in Microbial Diversity Using Magnetic and Density Separation. Geomicrobiology Journal, 29 (5). pp. 435-449. ISSN 0149-0451.

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This study introduces a new method for characterizing mineral-associated microbial diversity in sedimentary environments, a habitat that has been intrinsically challenging to study in regard to microbe-mineral interactions. Mineral components were enriched from bulk environmental samples by magnetic susceptibility or density separation techniques and used in subsequent molecular and microscopic analyses. Testing and optimization of the method was performed on geochemically-distinct sediment horizons from Eel River Basin methane seeps and pyrite and sphalerite-rich hydrothermal vent samples from the Lau Basin. Initial results show reproducible variations in microbial diversity between mineral fractions from marine sedimentary environments enriched in authigenic pyrite and/or transition metal-bearing clay minerals. Specifically, different archaeal clades associated with the anaerobic oxidation of methane and putative sulfate-reducing deltaproteobbacteria show preferential colonization patterns, suggesting potential ecophysiological differences between closely-related taxa. These results indicate that mineral colonization may influence the extent and distribution of microbial diversity throughout unconsolidated sediments of the marine subsurface. The combination of mineral separation and molecular analyses introduced here provide a new approach for revealing previously concealed patterns of mineral-associated microbial diversity across a wide range of environments, from hard rock habitats to fine-grained lithologies.

Item Type:Article
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URLURL TypeDescription DOIArticle
Orphan, Victoria J.0000-0002-5374-6178
Additional Information:© 2012 California Institute of Technology. Received 27 October 2010; accepted 4 April 2011. Available online: 05 Mar 2012. We thank the crew and shipboard parties and chief scientist B. Vrijenhoek of the R/V Melville (May, 2005) and R/V Atlantis (October, 2006) for support in sample collection. We also are grateful to S. Goffredi, A. Dekas, A. Green, J. Bailey, O. Mason, P. Tavormina, D. Fike, S. Connon, J. Steele and two anonymous reviewers for helpful comments and editorial advice. This work was supported by a grant from the Gordon and Betty Moore Foundation (to VJO), a Schlanger Ocean Drilling Graduate Fellowship (to BKH) and funding from the NASA Astrobiology Institute (Grant award # 3903-CIT-NASA.A76A) as part of the Penn State Astrobiology Research Center (PSARC). Collection of samples from the Eel River Basin and Lau Basin was supported by funding from the National Science Foundation (MCB-0348492 to VJO) and (OCE-0241613 to B. Vrijenhoek).
Funding AgencyGrant Number
Gordon and Betty Moore FoundationUNSPECIFIED
Schlanger Ocean Drilling Graduate FellowshipUNSPECIFIED
Subject Keywords:mineral separation; sulfate reduction; methane oxidation; sulfide mineralogy; hydrothermal vent
Issue or Number:5
Record Number:CaltechAUTHORS:20120518-133946986
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:31541
Deposited By: Tony Diaz
Deposited On:18 May 2012 21:10
Last Modified:03 Oct 2019 03:52

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