title: Influence of two-phase anaerobic digestion on fate of selected antibiotic resistance genes and class I integrons in municipal wastewater sludge.
abstract: The response of representative antibiotic resistance genes (ARGs) to lab-scale two-phase (acidogenic/methanogenic phase) anaerobic digestion processes under thermophilic and mesophilic conditions was explored. The associated microbial communities and bacterial pathogens were characterized by 16S rRNA gene sequencing. A two-phase thermophilic digestion reduced the presence of tetA, tetG, tetX, sul1, ermB, dfrA1, dfrA12 and intI1 exhibiting 0.1-0.72 log unit removal; in contrast, tetO, tetW, sul3, ermF and blaTEM even increased relative to the feed, and sul2 showed no significant decrease. The acidogenic phase of thermophilic digestion was primarily responsible for reducing the quantity of these genes, while the subsequent methanogenic phase caused a rebound in their quantity. In contrast, a two-phase mesophilic digestion process did not result in reducing the quantity of all ARGs and intI1 except for ermB and blaTEM. ARGs patterns were correlated with Proteobacteria and Actinobacteria during the two-phase anaerobic digestion.
authors.affiliation: Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, People's Republic of China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, People's Republic of China.
authors.forename: Erping
authors.initials: E
authors.lastname: Cui
authors.affiliation: Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, People's Republic of China.
authors.forename: Yiru
authors.initials: Y
authors.lastname: Zuo
authors.affiliation: Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, People's Republic of China.
authors.forename: Weixiao
authors.initials: W
authors.lastname: Cheng
authors.affiliation: Department of Plant and Environmental Sciences, University of Copenhagen, 1871 Frederiksberg, Denmark.
authors.forename: Christopher
authors.initials: C
authors.lastname: Rensing
authors.affiliation: Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, People's Republic of China. Electronic address: chen_hong@zju.edu.cn.
authors.forename: Hong
authors.initials: H
authors.lastname: Chen
mesh_terms: D000693:Anaerobiosis / Q000187:drug effects; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001105:Archaea / Q000187:drug effects / Q000235:genetics; D001419:Bacteria / Q000187:drug effects / Q000235:genetics; D019149:Bioreactors / Q000382:microbiology; D004352:Drug Resistance, Microbial / Q000187:drug effects / Q000235:genetics*; D005798:Genes, Bacterial; D032023:Integrons / Q000235:genetics*; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012722:Sewage / Q000382:microbiology*; D062065:Wastewater / Q000382:microbiology*; D018508:Water Purification / Q000379:methods*
chemical_list: D000900:Anti-Bacterial Agents; D012336:RNA, Ribosomal, 16S; D012722:Sewage; D062065:Wastewater
keywords: Antibiotic resistance genes; Bacterial community structure; Bacterial pathogens; Two-phase anaerobic digestion