Temperature impacts fate of antibiotic resistance genes during vermicomposting of domestic excess activated sludge.

Effect of temperature on antibiotic resistance genes (ARGs) during vermicomposting of domestic excess sludge remains poorly understood. Vermicomposting experiment with excess sludge was conducted at three different temperatures (15 °C, 20 °C, and 25 °C) to investigate the fate of ARGs, bacterial community and their relationship in the process. The vermicomposting at 25 °C did not significantly attenuate the targeted ARGs relative to that at 15 °C and 20 °C. The dynamics of qnr A, qnr S, and tet M genes during vermicomposting at 15 °C and 20 °C followed the first-order kinetic model. Temperature remarkably impacted bacterial diversity of the final products with the lowest Shannon index at 25 °C. The presence of the genus (Aeromonas and Chitinophagaceae) at 25 °C may contribute to the rebound of the genes (qnr A, qnr S and tet M). The study indicates that 20 °C is a suitable vermicomposting temperature to simultaneously reach the highest removal efficiency of the ARGs and the good biostability of the final product. [Display omitted] • Temperature variation affected the fate of ARGs during vermicomposting of domestic sludge. • Changes of qnr A, qnr S and tet G genes during vermicomposting at 15 °C and 20 °C followed the first kinetic model. • Host bacteria of ARGs differed with vermicomposting temperature. • 20 °C is a suitable temperature to reach the highest removal efficiency of the target ARGs and the good biostability of the final products. [ABSTRACT FROM AUTHOR]