“…They were enriched in nutrient additions in autumn, but not during spring or summer in eutrophic Lake Mendota (Newton and McMahon, ), and only at times of lowest phytoplankton biomass in a boreal lake (Peura et al ., ). Aeromonas hydrophila (Gammaproteobacteria) , known for its chitinolytic activity (Jagmann et al ., ), was readily enriched in freshwater microcosms amended with algal‐derived particles, but lost in direct competition assays against a strain affiliated with CF (Styp von Rekowski et al ., ). Thus, there are indications that the growth of opportunistic pelagic GAM is induced by recycled or allochthonous DOM sources and, to a lesser extent, also by phytoplankton exudates, but that they might be outcompeted by other taxa during algal blooms.…”