Annual variation of Microcystis genotypes and their potential toxicity in water and sediment from a eutrophic reservoir

• Published in: FEMS microbiology ecology Vol. 74; no. 1; pp. 93 - 102
• Main Authors: Kim, Song-Gun, Joung, Seung-Hyun, Ahn, Chi-Yong, Ko, So-Ra, Boo, Sung Min, Oh, Hee-Mock
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01.10.2010; Blackwell Publishing Ltd; Oxford University Press
• Subjects: Annual variations; Biodiversity; Concentration gradient; Cyanobacteria; Denaturing Gradient Gel Electrophoresis; DNA, Bacterial - isolation & purification; Ecology; Electrophoresis; Eutrophic environments; Eutrophic waters; Eutrophication; Fresh Water - chemistry; Fresh Water - microbiology; Gel electrophoresis; Genetic diversity; Genotype; Genotypes; Geologic Sediments - microbiology; Microbiology; Microcystins; Microcystins - analysis; Microcystis; Microcystis - genetics; Microcystis - growth & development; Microcystis genotype; Phylogeny; population diversity; Republic of Korea; Reservoirs; Seasons; Sediment samplers; Sediments; Sequence Analysis, DNA; Toxicity; Water bodies; Water pollution; Republic of Korea; Korea, Rep; Korea, Rep., Daechung Reservoir; toxicity; population diversity; cyanobacteria; genotype
• ISSN: 0168-6496; 1574-6941
• DOI: 10.1111/j.1574-6941.2010.00947.x

The relative genetic diversity of microcystin-producing Microcystis in the water and sediment of the Daechung Reservoir, Korea, was investigated over an entire year, including the cyanobacterial bloom season. The cells of potentially toxic Microcystis strains containing mcyJ genotypes and cells containing the genus-specific cpcBA gene were quantified by a real-time PCR. The ratio of cells with mcyJ genotypes to the total Microcystis population in the water body was the highest (68.3%) in August when the cyanobacterial bloom reached its peak and the microcystin concentration in the water began to increase. A denaturing gradient gel electrophoresis profile analysis of the mcyJ genotypes performed to monitor any changes in the toxic Microcystis population showed the appearance of new genotypes and the disappearance of existing genotypes in the reservoir water collected during the summer months, when compared with the profile for the samples collected in spring and autumn. However, very little change was observed over the course of the year as regards the population diversity of the sediment samples.