Phosphatase phoD gene community changes organic phosphorus in sediment from Caohai plateau wetland

Purpose The objective of this study was to investigate the characteristics of sediment organic phosphorus (P-o) driven by the microbial community during the ecological restoration of a plateau wetland. Materials and methods Twenty surface sediment samples were collected from the Caohai wetland, China. A series of analysis methods were used, including Ivanoff extraction, enzymatic hydrolysis, solution P-31 nuclear magnetic resonance (P-31-NMR), and high-throughput sequencing technology. Results The concentrations of the total P-o were in the range 564.66 to 751.30 mg kg(-1), among which Ful-P-o was the dominant component with a proportion of 38.67-45.37%. In the enzymatically hydrolyzable P-o, phosphomonoester was the main fraction accounting for 19.58-67.87%, while it made up 52.91-68.98% of the P-o determined by P-31-NMR. The biogeochemical feature of P-o indicated the high releasing risk of bioavailable P-o from the sediment to the overlying water in the Caohai plateau wetland. Anthropogenic input was the dominant source of P-o in the sediments, followed by the internal biological processes. Two thousand sixty-six OTUs were clustered in the phoD gene-harboring communities and were dominated by the Proteobacteria phylum and Rubrobacter genus. The redundancy analysis (RDA), correlation network analysis, and structural equation modeling (SEM) suggested the direct and/or indirect (coupling the C and N cycles) contribution of phoD gene communities to P fractions. Conclusion This study established the influence of microbes on P fractions and provided a valuable understanding of the biogeochemical cycling of P in sediment from an ecologically restored wetland.