Enumeration of Archaea and Bacteria in seafloor basalt using real-time quantitative PCR and fluorescence microscopy

Authors

  • Jørn Einen,

    1. Department of Biology, University of Bergen, Jahnebakken, Bergen, Norway
    2. Centre for Geobiology, University of Bergen, Allégaten, Bergen, Norway
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  • Ingunn H. Thorseth,

    1. Centre for Geobiology, University of Bergen, Allégaten, Bergen, Norway
    2. Department of Earth Science, University of Bergen, Allégaten, Bergen, Norway
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  • Lise Øvreås

    1. Department of Biology, University of Bergen, Jahnebakken, Bergen, Norway
    2. Centre for Geobiology, University of Bergen, Allégaten, Bergen, Norway
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  • Editor: Clive Edwards

Correspondence: Jørn Einen, Department of Biology, University of Bergen, Jahnebakken 7, 5007 Bergen, Norway. Tel.: +47 55 58 81 87; fax: +47 55 58 96 71; e-mail: jorn.einen@bio.uib.no

Abstract

A SYBR Green real-time quantitative PCR (Q-PCR) assay for the detection and quantification of Bacteria and Archaea present in the glassy rind of seafloor basalts of different ages and water depths is presented. Two sets of domain-specific primers were designed and validated for specific detection and quantification of bacterial and archaeal 16S rRNA genes in DNA extracted from basaltic glass. Total cell numbers were also estimated by fluorescence microscopy analysis of SYBR Gold-stained samples. The results from the two different approaches were concurrent, and Q-PCR results showed that the total number of cells present in basalts was in the range from 6 × 105 to 4 × 106 cells g−1 basaltic glass. Further, it was demonstrated that these cells were almost exclusively from the domain Bacteria. When applying the same methods on samples of different ages (22 years–0.1 Ma) and water depths (139–3390 mbsl), no significant differences in cell concentrations or in the relative abundance of Archaea and Bacteria were detected.

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