A synthetic microbial community for the enhanced removal of complex emerging pollutants from domestic wastewater

Pharmaceutical and personal care products (PPCPs) residues pose ecological and health risks due to their persistence and promotion of antibiotic resistance genes (ARGs) dissemination. Here, we constructed a synthetic microbial community (SMC) comprising two bacterial strains (Sphingopyxis sp. GC21 and Ochrobactrum sp. TCC-2) and one fungal strain (Apiotrichum sp. IB-1) for the enhanced simultaneous removal of three representative PPCPs: chloramphenicol (CAP), triclocarban (TCC), and naproxen (NPX) in simulated wastewater (SW) and real wastewater (RW). Under aerobic conditions, the removal efficiencies (REs) reached 97.83% for CAP, 68.19% for TCC, and 85.34% for NPX within 8 h in SW, while all REs exceeded 70% in RW. Under anoxic conditions, REs exceeded 60% for CAP, TCC and NPX both in SW and RW. The relative abundance of introduced Sphingopyxis was 6.45%, Ochrobactrum was 0.23%, and Apiotrichum was 51.06%, confirming successful colonization of them in the SMC reactor. They were responsible for the nitro-reduction and amide bond hydrolysis of CAP, two amide bonds hydrolysis of TCC, and O-demethylation and oxidation of NPX, which could detoxify these pollutants and promote cooperative degradation by indigenous microbial communities. Furthermore, SMC alleviated the selection pressure imposed by pollutants, thereby reducing the enrichment of mobile genetic elements and pathogens and suppressing the dissemination of ARGs. This study highlighted that SMC bioaugmentation provided an effective and sustainable strategy for mitigating complex PPCPs pollutions and controlling the spread of ARGs.