show Abstracthide AbstractLake Constance is the largest lake in Germany with a volume of 48 km3 and a maximum depth of 250 m. It is oligotrophic and has a permanently oxygenated hypolimnion throughout the year and serves as a drinking water reservoir for more than 5 million people. Samples were taken in 85m depth and was pre-filtered through a 70 and 30 micron nylon mesh and filtered on board onto 5 and 0.2 micron polycarbonate filters. DNA was extracted from 0.2 micron filters to obtain genomic DNA for metagenome sequencing.