Microcystis genotype succession in relation to microcystin concentrations in freshwater lakes
Harmful cyanobacteria ('blue-green algae') can form a serious threat in recreational waters and drinking-water reservoirs. The succession of toxic and nontoxic strains is poorly understood. Kardinaal and co-workers studied seasonal changes in genotype composition of the cyanobacterium Microcystis in 3 lakes, using molecular tools (rRNA of the ITS region combined with DGGE analysis). In 2 lakes, they observed seasonal replacement of various genotypes, but toxic genotypes dominated throughout the summer. In one lake, the seasonal succession started with a population consisting of several toxic genotypes, which were gradually replaced by non-toxic genotypes at the height of the summer bloom. The results demonstrate that changes in genotype composition may explain toxin dynamics of cyanobacterial blooms.
Inter-Research Science Center is pleased to make this Feature Article openly available for viewing by our readers.