Nanobubbles can modulate microbial communities and sedimentary ecosystem during the treatment of pond water

Nanobubbles are applied in diverse water-treatment technologies. However, their underlying mechanisms are not fully understood to date. In this study, we applied metagenomic approaches to investigate the effect of nanobubble treatment on the microbial communities in the pond aquatic ecosystem by systematic analysis of the metagenomes from different samples with spatial (water body and sediment) and temporal changes. We found that nanobubbles simultaneously changed the structure and balance of the microbial communities in the whole water body and sediment system during the pond water treatment. Importantly, nanobubble treatment inhibited harmful pathogenic microbes (mainly cyanobacterial species) and altered the diversity of microbial populations in the water body, while increasing the species richness in the sediments, providing a clue for understanding the mechanism of nanobubble effects.