Growth of Two Submersed Macrophytes Vallisneria natans and Vallisneria spinulosa Improving Water Quality and Affecting Microbial Communities in Both Sediments and Water Columns

Healthy aquatic ecosystems are essential for human beings, however, anthropogenic activities severely worsen the water quality. In this study, using assembling mesocosms, we employed an efficient and easy-to-handle method for monitoring water quality by detecting water electrical conductivity (EC). Our data demonstrate that the growth of two submersed macrophytes, Vallisneria natans and Vallisneria spinulosa, can improve water quality by decreasing EC. Further, using high-throughput DNA sequencing (HTS) technologies, we analyzed the microbial community abundance and structure in the sediments and water columns with or without these plant growths. We generated 33,775 ASVs from 69 samples belonging to four sediment groups (BkM, CtM, VnR and VsR) and three water column sample groups (CtW, VnW and VsW). The results show that the relative abundance of bacteria was higher in the sediment than in the water columns. Our data show that the diversity and composition of microbiomes were altered by Vallisneria spp. plant growth, and that the alpha-diversity of the microbial communities decreased due to submersed macrophytes in both the sediment and water columns. The beta-diversity of the microbial communities also varied significantly with or without Vallisneria spp. plant growth for both the sediment and water columns.