Background, Aims and Scope. Microbial electrolysis cells (MECs) system is an emerging pollution control technology. However, information on the variation of antibiotic resistance genes (ARGs) in MECs treating sewage sludge is still very limited.
Methods. MECs treating sludge were operated under different applied voltages (0-1.5V). Bioelectrode biofilms and suspended sludge samples were analyzed for ten frequently detected ARGs and microbial communities.
Results and Discussion. Most target ARGs were effectively removed. Distribution characteristics of microbial communities and their antibiotic resistance in MECs were revealed. Horizontal gene transfer was validated for the spread of sul1, sul2, tetA and tetC in MECs. Potential hosts of ARGs mainly belonged to Bacteroidetes, Firmicutes and Proteobacteria.
Conclusion. The selective pressure of residual antibiotics in the sewage sludge was negligible. MECs changed the community structure of potential ARGs hosts in traditional anaerobic sludge digestion.
Key words: Microbial electrolysis cells; Antibiotic resistance genes; Potential hosts; Antibiotic selective pressure |