title: Change in microbial community in landfill refuse contaminated with antibiotics facilitates denitrification more than the increase in ARG over long-term.
abstract: In this study, the addition of sulfamethazine (SMT) to landfill refuse decreased nitrogen intermediates (e.g. N2O and NO) and dinitrogen (N2) gas fluxes to <0.5 μg-N/kg-refuse·h-1, while the N2O and N2flux were at ~1.5 and 5.0 μg-N/kg-refuse·h-1respectively in samples to which oxytetracycline (OTC) had been added. The ARG (antibiotic resistance gene) levels in the refuse increased tenfold after long-term exposure to antibiotics, followed by a fourfold increase in the N2flux, but SMT-amended samples with the largest resistome facilitated the denitrification (the nitrogen accumulated as NO gas at ~6 μg-N/kg-refuse·h-1) to a lesser extent than OTC-amended samples. Further, deep sequencing results show that long-term OTC exposure partially substituted Hyphomicrobium, Fulvivirga, and Caldilinea (>5%) for the dominant bacterial hosts (Rhodothermus, ~20%) harboring nosZ and norB genes that significantly correlated with nitrogen emission pattern, while sulfamethazine amendment completely reduced the relative abundance of the "original inhabitants" functioning to produce NOxgas reduction. The main ARG carriers (Pseudomonas) that were substantially enriched in the SMT group had lower levels of denitrifying functional genes, which could imply that denitrification is influenced more by bacterial dynamics than by abundance of ARGs under antibiotic pressures.
authors.affiliation: Key Laboratory for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Science, East China Normal University, Shanghai 200241, China.|Joint Research Institute for New Energy and the Environment, East China Normal University and Colorado State University, Shanghai 200062, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Guanzhou
authors.initials: G
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Key Laboratory for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Science, East China Normal University, Shanghai 200241, China.|Joint Research Institute for New Energy and the Environment, East China Normal University and Colorado State University, Shanghai 200062, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Yang
authors.affiliation: Key Laboratory for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Science, East China Normal University, Shanghai 200241, China.|Joint Research Institute for New Energy and the Environment, East China Normal University and Colorado State University, Shanghai 200062, China.
authors.forename: Bing
authors.initials: B
authors.lastname: Xie
mesh_terms: D000900:Anti-Bacterial Agents / Q000378:metabolism*; D001673:Biodegradation, Environmental; D058440:Denitrification; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D020582:Hyphomicrobium / Q000235:genetics / Q000378:metabolism; D007218:Industrial Microbiology / Q000379:methods*; D064307:Microbiota; D010118:Oxytetracycline / Q000378:metabolism; D011549:Pseudomonas / Q000235:genetics / Q000378:metabolism; D012037:Refuse Disposal / Q000379:methods*; D013418:Sulfamethazine / Q000378:metabolism; D064091:Waste Disposal Facilities
chemical_list: D000900:Anti-Bacterial Agents; D013418:Sulfamethazine; D010118:Oxytetracycline