Deciphering the role of polyethylene microplastics on antibiotic resistance genes and mobile genetic elements fate in sludge thermophilic anaerobic digestion process

• PE-MP contributed to the spread of ARGs and MGEs in sludge AD process. Strong positive correlations between concentration ARGs/MGEs. reshaped structure composition microbial community. Potential host was identified through co-occurrence networks. Structural equation model quantified contribution MGEs. The retention microplastics sewage sludge, a reservoir antibiotic resistance genes (ARGs) mobile genetic elements (MGEs), has attracted increasing attention. However, impact polyethylene (PE-MP) on fate is far from fully understood sludge's thermophilic anaerobic digestion process (AD). present study demonstrated that with size 40-48 µm at concentrations 50, 100, 200 particles/g-TS could enlarge total abundance. Meanwhile, significant (r = 0.96, p < 0.05) correlation observed content. Microbial analysis revealed enrichment some functional genus under stress PE-MP, which might be potential relative abundance acetogens Thermoanaerobacter increased 27.60% 32.80% hydrolytic bacteria Caldicoprobacter enriched by 28.03% when content zero particles/g-TS. hosts were subsequently networks, as pathogens. ARGs, using redundancy analysis. Additionally, structural indicated direct indirect influence enhance acquisition dissemination directly. Taking together, our findings deciphered process, pose risks human health should considered during disposal.