..Water samples for microscopic analysis were collected on 17 March and 20 April 2010 at ca. 0.5m depth from the water level pier at the southeast end of the lake (Figure 1). Three replicates of selleckchem 500mL each were collected in polyethylene bottles. Two of them were fixed with Lugol’s solution and formaldehyde, while one was retained fresh for direct microscopic analysis. Water temperature, dissolved oxygen, salinity, and pH were measured in situ using a WTW sensor (Weilheim, Germany).For each sampling date, at least three replicates of live and preserved samples were examined in sedimentation chambers using an inverted microscope with phase contrast (Nikon SE 2000). Cyanobacteria and microscopic eukaryotes were identified using classical taxonomic keys and previous works [20�C23].

Phytoplankton counts (cells, colonies, and coenobia) were performed using the Uterm?hl’s sedimentation method [24]. For biomass (mgL?1) estimation, the dimensions of 30 individuals (cells, filaments, or colonies) of each species were measured using tools of a digital microscope camera (Nikon DS-L1), while mean cell or filament volume estimates were calculated using appropriate geometric formulae, as described previously [25, 26]. Species and taxonomical groups comprising more than 10% (w/w) of the total phytoplankton biomass were considered to be dominant.Water samples for DNA extraction were transported to the laboratory in 4-L collapsible plastic bottles (Nalgene, Rochester NY, USA) and processed within 1h of collection. After screening through a 180��m mesh net to exclude larger eukaryotes and particles, 200�C250mL of water was filtered through a 0.

2��m pore size Polycarbonate Isopore filter (Sartorius, Goettingen, Germany). The filtration was conducted under reduced pressure (��100mmHg) to prevent cell damage. Filters were stored immediately at ?80��C until further analysis.DNA was extracted using the UltraClean Soil DNA isolation kit (MoBio Laboratories, Carlsbad CA, USA) according to the manufacturer’s protocol after slicing the filter with a sterile scalpel. The concentration of bulk DNA was estimated by spectrophotometry (NanoDrop ND-1000, NanoDrop Technologies, Wilmington DE, USA) and ranged between 11.9 and 15.4ng��L?1 for the March and April samples, respectively. For AV-951 PCR amplification, approximately 12ng of environmental DNA was used as template for both samples. The 18S rRNA gene was amplified using the eukaryote specific primers EukA (5��-AACCTGGTTGATCCTGCCAGT-3��) and EukB (5��-GATCCTTCTGCAGGTTCACCTAC-3��) [27] for the March sample, while the primers EukA and Euk1633rE (5��-GGGCGGTGTGTACAARGRG-3��) [28] were used for amplification of the 18S rRNA gene for April sample.