Tire wear particles (TWPs) attract attention because of their harmful impact on the soil ecosystem. Nevertheless, there is limited understanding regarding how aging affects the toxicity of TWPs to soil microorganisms. Herein, a microcosm experiment was performed to compare the toxicity of pristine and UV-aged TWPs on the soil microbial community. After 28 days operation, more holes and cracks appeared on the surface of the UV-aged TWPs compared with the pristine TWPs. The diversity and community structure of soil microorganisms changed under the pristine and UV-aged TWPs exposure, with the UV-aged TWPs significantly altered nirK-type soil denitrifying bacteria. Streptomyces played an important role in connecting the nirK-type bacterial community and promoting the denitrification process under the UV-aged TWPs exposure. The soil microorganisms further promoted the membrane transport of metabolites to resist the toxic effects of UV-aged TWPs by up-regulating the ATP-binding cassette (ABC) transporters, which consumed lots of energy and led to interference in energy metabolism. Furthermore, UV-aged TWPs further stimulated the accumulation of reactive oxygen species (ROS), stimulated the soil microorganisms to secrete more extracellular polymers substances (EPS) and activated the antioxidant defense system against oxidative damage caused by UV-aged TWPs, however, the activation of SOS response in turn increased the risk of antibiotic resistance genes (ARGs) transmission.

More information is needed to fully comprehend how acid mine drainage (AMD) affects the phototransformation of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in karst water and sewage -irrigated farmland soil with abundant carbonate rocks (CaCO 3 ) due to increasing pollution of AMD formed from pyrite (FeS 2 ). The results showed FeS 2 accelerated the inactivation of ARB with an inactivation of 8.7 log. Notably, extracellular and intracellular ARGs and mobile genetic elements (MGEs) also experienced rapid degradation. Additionally, the pH of the solution buffered by CaCO 3 significantly influenced the photo -inactivation of ARB. The Fe 2 + in neutral solution was present in Fe(II) coordination with strong reducing potential and played a crucial role in generating center dot OH (7.0 mu M), which caused severe damage to ARB, ARGs, and MGEs. The center dot OH induced by photo -Fenton of FeS 2 posed pressure to ARB, promoting oxidative stress response and increasing generation of reactive oxygen species (ROS), ultimately damaging cell membranes, proteins and DNA. Moreover, FeS 2 contributed to a decrease in MIC of ARB from 24 mg/L to 4 mg/L. These findings highlight the importance of AMD in influencing karst water and sewage -irrigated farmland soil ecosystems. They are also critical in advancing the utilization of FeS 2 to inactivate pathogenic bacteria.