Aquatic Sciences Meeting, Albuquerque 2001

SS04 Environmental Microbial Genomics (Environmental and Disciplinary Connections)

Date: Wednesday, February 14, 2001, Time: 12:15:00 PM

Location: Brazos

Keough, B, P, University of Minnesota Duluth, Duluth, USA, bkeough@d.umn.edu

Hicks, R, E, University of Minnesota Duluth, Duluth, USA, rhicks@d.umn.edu

PRESENCE AND PHYLOGENETIC AFFILIATION OF ARCHAEAL NUCLEIC ACIDS FROM PICOPLANKTON OF GREAT LAKES

Recent surveys of microbial diversity worldwide have revealed the presence of a poorly understood group of procaryotes, the Archaea. Archaeons were thought to be primarily extremophilic but evidence now suggests they are common in many terrestrial and aquatic habitats. Quantitative hybridizations with 16S rRNA-based probes revealed that up to 10% of picoplanktonic nucleic acid may be of archaeal origin in the Laurentian Great Lakes, Lakes Ladoga and Onega in Russia, and Lake Victoria in Africa. The presence of these archaeal nucleic acids was independently verified for most lakes by archaeal-specific PCR amplification of rDNA. Two approaches, top-down hybridization and sequencing of rDNA clones, were used to identify the phylogenetic affiliations of the archaeal nucleic acids. In most lakes, a very small amount of nucleic acid from the Group I crenarchaeotal marine cluster was found. Sequence analysis of rDNA clones may reveal the presence of other archaeal taxa. Our results extend the range of archaeons to picoplankton in large lake ecosystems.

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Aquatic Sciences Meeting, Albuquerque 2001

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