Fate of antibiotic resistance genes during temperature-changed psychrophilic anaerobic digestion of municipal sludge.

Affiliation

Yun H(1), Liang B(2), Ding Y(3), Li S(1), Wang Z(1), Khan A(1), Zhang P(4), Zhang P(4), Zhou A(5), Wang A(6), Li X(7).
Author information:
(1)Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, Gansu, China; Key Laboratory for Resources Utilization Technology of Unconventional Water of Gansu Province, Gansu Academy of Membrane Science and Technology, Lanzhou 730020, China; Gansu Key Laboratory of Biomonitoring and Bioremediation for Environment Pollution, School of Life Sciences, Lanzhou University, Lanzhou 730000, Gansu, China.
(2)School of Civil & Environmental Engineering, Harbin Institute of Technology
(Shenzhen), Shenzhen, 518055, China. Electronic address: [Email]
(3)Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
(4)Key Laboratory for Resources Utilization Technology of Unconventional Water of Gansu Province, Gansu Academy of Membrane Science and Technology, Lanzhou 730020, China.
(5)College of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan, 030024, China.
(6)School of Civil & Environmental Engineering, Harbin Institute of Technology
(Shenzhen), Shenzhen, 518055, China; Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
(7)Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, Gansu, China; Key Laboratory for Resources Utilization Technology of Unconventional Water of Gansu Province, Gansu Academy of Membrane Science and Technology, Lanzhou 730020, China; Gansu Key Laboratory of Biomonitoring and Bioremediation for Environment Pollution, School of Life Sciences, Lanzhou University, Lanzhou 730000, Gansu, China. Electronic address: [Email]

Abstract

The effects of anaerobic digestion (AD) on the abundance of antibiotic resistance genes (ARGs) are highly related to operational temperature. However, the removal performance of ARGs in psychrophilic AD and changed temperatures simulating variable seasonal temperatures is poorly understood. Herein, we investigated the fate of ARGs, correlated bacterial communities and physicochemical properties of AD operation at psychrophilic (15 ℃), mesophilic (35 ℃), and temperature changed conditions (15 to 35 ℃ and 35 to 15 ℃). The results indicated that ammonia release was positively correlated with temperature. The mesophilic AD facilitated phosphorous intake and ARGs proliferation and selection with oxytetracycline (OTC), while psychrophilic AD was conducive to the removal and control of ARGs if no OTC existed. The diversity and composition of AD bacterial communities were influenced more by temperature than OTC. The dominant genera like Candidatus_Microthrix and Acinetobacter had dramatical abundance discrepancies at different temperatures and were obviously positively correlated with ARGs (tet39, tetC and mexD), mobile genetic elements (MGEs) intI, insert sequences (IS) and plasmid. The physicochemical properties of AD influenced the bacterial richness, which in turn significantly correlated with the ARGs abundances. Therefore, ARGs removal could be potentially optimized by eliminating bacterial hosts with deteriorated living conditions and decreased nutrients. This study clarified the response of antibiotic resistome to different temperature variation and highlighted the potential strategies for improved ARGs removal in AD.