Bacterial dynamics in spring water of alpine karst aquifers indicates the presence of stable autochthonous microbial endokarst communities

Authors

  • Andreas H. Farnleitner,

    Corresponding author
    1. Institute of Chemical Engineering, Research Area Gene Technology and Applied Biochemistry, Vienna University of Technology, Getreidemarkt 166-9, A-1060 Vienna, Austria.
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  • Ines Wilhartitz,

    1. Institute of Chemical Engineering, Research Area Gene Technology and Applied Biochemistry, Vienna University of Technology, Getreidemarkt 166-9, A-1060 Vienna, Austria.
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  • Gabriela Ryzinska,

    1. Institute of Chemical Engineering, Research Area Gene Technology and Applied Biochemistry, Vienna University of Technology, Getreidemarkt 166-9, A-1060 Vienna, Austria.
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  • Alexander K. T. Kirschner,

    1. Centre for Anatomy and Cell Biology, Medical University Vienna, Waehringerstr. 10, A-1090 Vienna, Austria.
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  • Hermann Stadler,

    1. Institute of Water Resource Management, Joanneum Research, Elisabethstr. 16/II, A-8010 Graz, Austria.
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  • Martina M. Burtscher,

    1. Institute of Chemical Engineering, Research Area Gene Technology and Applied Biochemistry, Vienna University of Technology, Getreidemarkt 166-9, A-1060 Vienna, Austria.
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  • Romana Hornek,

    1. Institute of Chemical Engineering, Research Area Gene Technology and Applied Biochemistry, Vienna University of Technology, Getreidemarkt 166-9, A-1060 Vienna, Austria.
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  • Ulrich Szewzyk,

    1. Microbial Ecology Group, University of Technology, Berlin, Franklinsstr. 29, D-10587 Berlin, Germany.
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  • Gerhard Herndl,

    1. Netherlands Institute for Sea Research, Department of Biological Oceanography, 1790 AB Den Burg, Texel, the Netherlands.
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  • Robert L. Mach

    1. Institute of Chemical Engineering, Research Area Gene Technology and Applied Biochemistry, Vienna University of Technology, Getreidemarkt 166-9, A-1060 Vienna, Austria.
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*E-mail A.Farnleitner@aon.at; Tel. (+43) 1 58801 17251; Fax (+43) 1 5816266.

Summary

Spring water of two alpine karst aquifers differing in hydrogeology but of nearby catchments were investigated for their bacterial population dynamics. Dolomite karst aquifer spring 1 (DKAS 1) represents a dolomitic-limestone karst aquifer spring showing high average water residence time and relative constant flow. Limestone karst aquifer spring 2 (LKAS 2) constitutes a typical limestone karst aquifer spring with a dynamic hydrological regime and discharge. Dolomite karst aquifer spring 1 yielded constantly lower cell counts and biomasses (median of 15 × 106 cells l−1 and 0.22 µg C l−1) as the LKAS 2 (median of 63 × 106 cells l−1 and 1.1 µg C l−1) and distribution of morphotypes and mean cell volumes was also different between the considered systems, indicating the influence of hydrogeology on microbial spring water quality. Molecular bacterial V3 16S-rDNA profiles revealed remarkable constancy within each spring water throughout the investigation period. Time course analysis of a flood event in LKAS 2 further supported the trend of the temporal constancy of the microbial community. Except for one case, retrieval of partial and full length 16S rDNA gene sequences from the relative constant DKAS 1 revealed similarities to presently known sequences between 80% to 96%, supporting the discreteness of the microbial populations. The gathered results provide first evidence for the presence of autochthonous microbial endokarst communities (AMEC). Recovery of AMEC may be considered of relevance for the understanding of alpine karst aquifer biogeochemistry and ecology, which is of interest as many alpine and mountainous karst springs are important water resources throughout the world.

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