Freshwater lake Constance Cyanobacteria Raw sequence reads

Freshwater autotroph primary producers play a key role in the well functioning of the ecosystem. They synthetise organic molecules form inorganic molecules and provide nutrient for higher trophic levels organisms. Freshwater primary producers are composed of algae, unicellular algae and Cyanobacteria. Only few studies focusing on Cyanobacteria have been done on lake Constance and no analysis using new omics techniques were conducted yet. The goal of this study is to have a better understanding of the Cyanobacteria community composition and temporal dynamic in lake Constance using molecular tools. A more specific focus was also done on the microcystin-producing Cyanobacteria: Plankthtorix and Microcystis genus. These cyanobacteria are responsible of the formation of toxic bloom in deep stratified prealpine lake like lake Zurich, lake Geneva, lake Bourget etc, that impact the lake fauna and can constitute a potential health problem for human populations. Until now lake Constance did not seems to have experience toxic Planktothrix bloom although its topography is fitting the requirement of bloom formation. Samples were taken at the phycoerythrin maximal concentration depth and microplankton was collected by filtration. After DNA extraction, 16S rRNA gene was amplified using cyanobacteria specific primers and was send for Illumina MiSeq sequencing. In parallel, toxin detection was carried out by UPLC-MS/MS and microcystin-synthesis genes were amplified and sequenced by Sanger sequencing.