High-throughput sequencing of 16S and 18S rRNA genes, as well as metagenomic sequencing, were employed to investigate the shifts in bacterial and protist community compositions, as well as nitrogen cycling-related genes, during the process of nitrogen removal in the sea water within ecological floating beds of Sesuvium portulacastrum L. Our findings revealed that nitrogen in eutrophic water can be effectively removed within a few days by utilizing floating beds. Throughout the nitrogen removal process in eutrophic water, we observed fluctuations in microbial community compositions, species richness, and co-occurrence networks. Notably, we found that the bacterial and protist communities within the floating beds exhibited a stronger symbiotic relationship and greater stability. Furthermore, following the implementation of floating beds, there was an increase in the capacity for nitrogen cycling in the water which subsequently promoted denitrification processes. This facilitated both migration and transformation of nitrogen compounds while also aiding in removing nitrogen-containing pollutants from eutrophic waters - ultimately leading to environmental improvement. Our research provides new insights into understanding microbial community dynamics during ecological floating bed-mediated nitrogen removal processes and offers potential applications for restoring eutrophic aquatic ecosystems.

protist communities,ecological floating beds,bacterial communities