1. Department of Ecology and Genetics/Limnology; Uppsala University; Uppsala SE 75236 Sweden
2. Department of Biology/Aquatic Ecology; Lund University; Lund, Sölvegatan 37 SE 22362 Sweden
3. Centre for Ecology and Evolution in Microbial model Systems - EEMiS; Linnaeus University; Kalmar, SE 39231 Sweden