Kardinaal, W.E.A. and Janse, I. and Kamst-van Agterveld, M.P. and Meima, M. and Snoek, J. and Mur, L.R. and Huisman, J. and Zwart, G. and Visser, P.M. (2007) Microcystis genotype succession in relation to microcystin concentrations in freshwater lakes. Aquatic Microbial Ecology, 48, 1-12. ISSN 0948-3055.
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Official URL: http://www.int-res.com/abstracts/ame/v48/n1/p1-12/
Potentially toxic Cyanobacteria, like Microcystis, form a serious threat in recreational waters and drinking-water reservoirs. We monitored the population dynamics of toxic and non-toxic Microcystis strains using rRNA of the internal transcribed spacer region in combination with DGGE to determine whether there is a seasonal succession of toxic and non-toxic Microcystis genotypes in freshwater lakes and, if so, whether this succession can explain seasonal dynamics of the toxin microcystin. We studied 3 lakes in The Netherlands, all dominated by Microcystis during summer. Coexistence of several genotypes was observed in all lakes. The seasonal succession in a deep, stratified lake started with a population consisting of several toxic genotypes at the onset of the bloom, which changed into a population dominated by non-toxic genotypes at the end of the bloom. In this lake, the genotype succession clearly accounted for the observed microcystin dynamics. In 2 unstratified lakes, we also observed a seasonal replacement of Microcystis genotypes; however, the relation between genotype succession and microcystin dynamics was less conspicuous, since toxic strains dominated throughout the bloom period. A seasonal succession of different Microcystis genotypes might often be a key mechanism determining microcystin concentrations in Microcystisdominated lakes. Therefore, factors driving the succession of toxic and non-toxic genotypes deserve further study.
|Institutes:||Nederlands Instituut voor Ecologie (NIOO)|
|Deposited On:||16 Sep 2009 02:00|
|Last Modified:||18 Oct 2011 10:34|
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