Phycosphere microbiome assembly in long-term algal cultures: effects of culture history and co-culture

This study investigates the structure and assembly of bacterial communities associated with filamentous freshwater green algae maintained under long-term laboratory cultivation. Amplicon sequencing of the 16S rRNA gene was used to characterize prokaryotic microbial communities associated with non-axenic algal cultures. The study includes two complementary experiments. In the first experiment, a panel of algal strains from multiple culture collections was analyzed to evaluate the relative importance of host taxonomy and cultivation history in shaping associated microbiomes under common laboratory conditions. In the second experiment, two filamentous algal strains were grown in co-culture and subsequently re-isolated to examine microbiome mixing, exchange, and the persistence of host-associated microbial taxa following co-cultivation.