Co-occurrence network in core microorganisms driving the transformation of phosphorous fractionations during phosphorus recovery product used as soil fertilizer.

Phosphorus recovery from water and the subsequent reuse of its products can solve both water eutrophication and phosphorus resource waste issues. However, the potential use of the final recovered products as crop phosphorus fertilizers and the transformation of phosphorus fractions in soils have rarely been analyzed. In this study, the effects of a phosphorus recovery product (w-HC/CSH/P) obtained from our previous phosphorus recovery study on pepper growth were investigated. The association between soil phosphorus fraction transformation and the microbial co-occurrence network was investigated using high-throughput sequencing. The results showed that amendment with w-HC/CSH/P could promote the growth and chlorophyll content of pepper, which exhibited high phosphorus fertilizer efficiency. In addition, applying w-HC/CSH/P in soils could increase the microbial alpha-diversity during pepper cultivation and induce changes in the microbial community, leading to an increase in the relative abundance of Povalibacter, Lysobacter, and GP10 and a decrease in GP17. The proportion of Resin-P and NaHCO-P decreased, whereas that of NaOH-P increased during pepper cultivation. psOTU331 (g_Latescibacteria), psOTU377 (g_Lysobacter), and psOTU461 (g_Pseudoxanthomonas) were the key microorganisms driving the transformation of phosphorus fractionation in the microbial co-occurrence network. Latescibacteria and Lysobacter were closely correlated with the transformation of NaHCO-P to NaOH-P, and Pseudoxanthomonas was significantly correlated with a decrease in Resin-P. These observations highlight the potential of phosphorus recovery products as fertilizer for pepper and provide new insights into the transformation of phosphorus fractions corresponding to the microbiome in soils.