An integrated Metagenomic-Pangenomic strategy revealed native microbes and magnetic biochar cooperation in plasticizer degradation

There has been growing concern over the release of plasticizers from plastic products, and the high levels of plasticizers in the environment have led to a threat to ecological security. Although some plasticizers may naturally degrade, their slow removal and prolonged life cycle remain challenges. To address this, this study explored a unique hybrid strategy using native field microorganisms and magnetic biochar (MBC) to support the upstream degradation of plasticizers. Diethyl phthalate (DP) was used as the test subject. The study found that MBC treatment led to high level of total organic carbon (TOC) and various organic products, demonstrating the degradation of DP. Analysis of the hybrid metagenomic model showed that several species of Pseudomonas can degrade downstream phenylmethanal and Pseudomonas nitroreducens has the ability to cooperate well with MBC due to its iron receptor and transporter. Additionally, a Pigmentiphaga species was found to have the ability to fully mineralize DP. Analysis of the Pigmentiphaga pangenome revealed that genes related to DP biodegradation were shared by members of this genus. Although some members of Pseudomonas is known to be pathogenic, the species identified in the study may not be harmful as they lack virulence factors. The study provides evidence regarding the cooperation between native biodegraders and MBC in mineralizing plasticizers, offering a new solution for removing phthalate plasticizers from soil and surface water.