AME 15:89-96 (1998)  -  doi:10.3354/ame015089

Distribution and origin of dissolved DNA in lakes of different trophic states

Waldemar Siuda1,*, Ryszard J. Chróst1, Hans Güde2

1Department of Microbial Ecology, Institute of Microbiology, University of Warsaw, ul. Karowa 18, PL-00-325 Warsaw, Poland
2Institut für Seenforschung, Untere Seestr. 81, D-88081 Langenargen, Germany

Concentrations and origin of dissolved DNA (dDNA) were studied in 14 lakes in the Mazurian Lake District (Northern Poland) and 7 lakes in Southern Germany during the summer stratification period. dDNA concentration varied markedly (from 0.5 to 70 μg l-1) in the studied lakes. We suggest that this dissolved organic matter fraction can be potentially one of the most important P and N sources for planktonic microorganisms. Laboratory experiments and field observations suggested that eukaryotic microorganisms (algae) are the most important sources of dDNA in lake water, whereas bacteria mainly decompose the dDNA pool.

Dissolved DNA · Trophic status index of lake · Algae · Bacteria · Primary production · Secondary production

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