Elucidating the picocyanobacteria salinity divide through ecogenomics of new freshwater isolates. Synechococcus / Cyanobium

To expand the coverage of available freshwater picocyanobacterial genomes (cluster 5 Synechococcus and Cyanobium genera), we obtained cultures from various lakes and reservoirs over various years of isolation campaigns, including isolates from several continents (north Asia, west and central Europe, south-east Oceania, Central America and South America). Isolates also covered a range of trophic regimes, from oligotrophic lakes like Lake Baikal (Russia) or Tous reservoir (Spain) to meso-eutrophic habitats such as Amadorio reservoir (Spain) or Lake Chascomus (Argentina), and encompassing cold and glacial lakes, temperate reservoirs and tropical lakes. In total, we sequenced the genomes of 58 new isolates resulting in 32 new species (based on the 95 % of Average Nucleotide Identity, - ANI - threshold) that greatly expand the current number of complete or near-complete freshwater picocyanobacterial genomes.