Water-logged composting with sealed system enhances phosphorus availability and changes ecological attributes of...

Deciphering effects of sealed environment on phosphorus (P) availability and microbial community during water-logged composting is an essential but underestimated theme. Research targets are to unveil divergences in P fractions and bacterial landscapes between breathable and sealed systems using molecular and statistical tools. Water-logged composting with sealed system enhanced P availability, with soluble reactive P in overlying water notably increasing from 1.20 to 1.92 mg L^-1 and available P in composting substrate significantly arising from 1.61 to 2.28 g kg^-1. Higher abundances of organic P (Po)-mineralizing genes, including β-propeller phytase-encoding gene of bpp, acid phosphatase-encoding gene of phoC, alkaline phosphatase-encoding gene of phoD, and phosphonoacetaldehyde hydrolase-encoding gene of phnX, were found in sealed system than in breathable system. Bacterial community composition varied notably between sealed and breathable systems, with dominant bacterial phyla of Proteobacteria and Actinobacteriota in overlying water were notably more abundant in sealed and breathable systems, respectively. Bacteria in sealed system rather than breathable system displayed higher community complexity and stability, stronger migration potential and phylogenetic signal, and were affected more by determinism. Our findings highlight ecological consequences of water-logged composting with sealed system, and these findings might guide composting in a water-logged way to obtain P fertilizer.