Transmission and regulation insights into antibiotic resistance genes in straw-sludge composting system amended with calcium peroxide

This study developed a Fenton-like system by adding calcium peroxide (CaO2) to a composting system containing straw and sludge. The objective was to examine the influence of antibiotic resistance genes (ARGs) and the structure of the bacterial community. The findings indicated that the inclusion of CaO2 facilitated the reduction of ARGs. ARGs abundance in the test group (T) with CaO2 was 19.02% lower than that in the control check group (CK) without CaO2, and the abundance of ARGs in both groups after composting was lower than the initial abundance. Additionally, the structure of bacterial community in both groups underwent significant changes. Redundancy analysis (RDA) revealed that the CaO2-induced Fenton-like reaction predominantly affected temperature, pH, and the bacterial community by means of reactive oxygen species (ROS). In conclusion, the addition of CaO2 enhanced the removal of ARGs from sewage-sludge and improved compost quality in the composting.