The toxic cyanobacterium Microcystis causes worldwide health concerns, being frequently found in freshwater and estuarine ecosystems. Under natural conditions, Microcystis spp. show a colonial lifestyle involving a phycosphere populated by a highly diverse associated microbiome. In a previous study, we have proposed that colony formation and growth may be achieved through mechanisms of multispecies bacterial biofilm formation. Starting with single-cells, specific bacteria would be recruited from the environment to attach and create a buoyant biofilm or colony.