Archaea in the Gulf of Aqaba

Authors

  • Danny Ionescu,

    1. Department of Plant and Environmental Sciences, The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
    2. The School for Marine Sciences, The Ruppin Academic Center, Emek-Hefer, Israel
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  • Sigrid Penno,

    1. Department of Plant and Environmental Sciences, The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
    2. H. Steinitz Marine Biology Laboratory, The Interuniversity Institute for Marine Sciences, Eilat, Israel
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  • Maya Haimovich,

    1. Department of Plant and Environmental Sciences, The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
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  • Branko Rihtman,

    1. Department of Plant and Environmental Sciences, The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
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  • Aram Goodwin,

    1. Earth Sciences Institute, The Hebrew University of Jerusalem, Jerusalem, Israel
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  • Daniel Schwartz,

    1. The Faculty of Biology, The Technion, Haifa, Israel
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  • Lena Hazanov,

    1. Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
    2. H. Steinitz Marine Biology Laboratory, The Interuniversity Institute for Marine Sciences, Eilat, Israel
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  • Mark Chernihovsky,

    1. Department of Plant and Environmental Sciences, The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
    2. H. Steinitz Marine Biology Laboratory, The Interuniversity Institute for Marine Sciences, Eilat, Israel
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  • Anton F. Post,

    1. Department of Plant and Environmental Sciences, The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
    2. H. Steinitz Marine Biology Laboratory, The Interuniversity Institute for Marine Sciences, Eilat, Israel
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  • Aharon Oren

    1. Department of Plant and Environmental Sciences, The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
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  • Editor: Patricia Sobecky

Correspondence: Danny Ionescu, Department of Plant and Environmental Sciences, The Institute of Life Sciences, The Hebrew University of Jerusalem, 91904 Jerusalem, Israel. Tel.: +972 2 658 5135; fax: +972 2 658 4425; e-mail: danny.ionescu@mail.huji.ac.il

Abstract

Using a polyphasic approach, we examined the presence of Archaea in the Gulf of Aqaba, a warm marine ecosystem, isolated from major ocean currents and subject to pronounced seasonal changes in hydrography. Catalyzed reported deposition FISH analyses showed that Archaea make up to >20% of the prokaryotic community in the Gulf. A spatial separation between the two major phyla of Archaea was observed during summer stratification. Euryarchaeota were found exclusively in the upper 200 m, whereas Crenarchaeota were present in greater numbers in layers below the summer thermocline. 16S rRNA gene-based denaturing gradient gel electrophoresis confirmed this depth partitioning and revealed further diversity of Crenarchaeota and Euryarchaeota populations along depth profiles. Phylogenetic analysis showed pelagic Crenarchaeota and Euryarchaeota to differ from coral-associated Archaea from the Gulf, forming distinct clusters within the Marine Archaea Groups I and II. Endsequencing of fosmid libraries of environmental DNA provided a tentative identification of some members of the archaeal community and their role in the microbial community of the Gulf. Incorporation studies of radiolabeled leucine and bicarbonate in the presence of different inhibitors suggest that the archaeal community participates in autotrophic CO2 uptake and contributes little to the heterotrophic activity.

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