Mechanisms of total phosphorus removal and reduction of β-lactam antibiotic resistance genes by exogenous fungal combination activated sludge

This study utilized Trichoderma and activated sludge to construct combined activated sludge (TAS). The metagenomic approach was employed to examine the shifts in microbial community structure and function of TAS under amoxicillin stress and investigate the mechanism underlying the reduction of beta-lactam antibiotic resistance genes (beta-ARGs). The findings demonstrated that the elevated aundance of glpa, glpd, ugpq, glpq, and glpb were primarily responsible for the reduction in total phosphorus (TP) removal by TAS. The increased abundance of Proteobacteria and Verrucomicrobia led to enhanced expression of ugpb, phnd, and phne, thereby improving the TP removal of TAS. Furthermore, antibiotic inactivation has gradually become the primary antibiotic resistance mechanism in TAS. Specifically, an increase in the abundance of OXA-309 in TAS will decrease the probability of amoxicillin accumulation in TAS. A decrease in beta-ARGs diversity confirmed this. This study presents a novel approach to reducing antibiotic and ARG accumulation in sludge.

Automated summary

This study used Trichoderma and activated sludge to construct combined activated sludge (TAS) and employed a metagenomic approach to investigate the shift in microbial community structure and function of TAS under amoxicillin stress. The findings revealed that increased abundance of certain genes contributed to the reduction in total phosphorus removal by TAS, while increased abundance of specific bacterial phyla improved TP removal. Furthermore, antibiotic inactivation has become the primary antibiotic resistance mechanism in TAS.