Illuminating the ecology of freshwater picocyanobacteria through a genome-resolved taxonomic framework

Although picocyanobacteria (Pcy) are viewed as one of the quintessential players in the Global Carbon Cycle (through fueling World's Oceans primary production), our apprehension of their ecology in freshwater ecosystems strongly lags behind. We reason that one of the main impediments in elucidating their impact and importance, in lacustrine habitats, stems from the lack of means necessary to delineate ecologically-relevant taxonomical units (e.g. species and subspecies). Thus, we intend to surpass the existing taxonomical bottleneck, of microscopy-based taxa description and 16S rRNA gene-orientated species delineation, through developing a robust genomic-centered classification framework. We intend to build on our existing freshwater Pcy collection (already containing more than 120 strains) and to use state-of-the-art shotgun sequencing in order to obtain approx. 100 high-quality genomes. This extent of genomic data will also provide the means necessary to track discrete populations in the natural environment (through CARD-FISH targeting) and disentangle their food web role.