title: Altitude-scale variation in nitrogen-removal bacterial communities from municipal wastewater treatment plants distributed along a 3600-m altitudinal gradient in China.
abstract: Microbial ecological information on the nitrogen removal processes in wastewater treatment plants (WWTPs) has been of considerable importance as a means for diagnosing the poor performance of nitrogen removal. In this study, the altitude-scale variations in the quantitative relationships and community structures of betaproteobacteria ammonia-oxidizing bacteria (βAOB) and nitrite-reducing bacteria containing the copper-containing nitrite reductase gene (nirK-NRB) and the cytochrome cd1-containing nitrite reductase gene (nirS-NRB) were investigated in 18 municipal WWTPs distributed along a 3660-masl altitude gradient in China. An altitude threshold associated with the proportions of NRB to total bacteria, NRB to βAOB and nirK-NRB to nirS-NRB was detected at approximately 1500m above sea level (masl). Compared with the stable proportions below 1500masl, the proportions exhibited a pronounced decreasing trend with increased altitude above 1500masl. Spearman correlation analysis indicated that the trend was significantly driven by altitude as well as multiple wastewater and operational variables. The community structure dissimilarity of βAOB, nirK-NRB and nirS-NRB showed significant and positive correlations with altitudinal distance between WWTPs. Redundancy analyses indicated that the variation in community structures above 1500masl were predominantly associated with wastewater, followed by operation and altitude. In summary, although the variations of nitrogen-removal bacterial community in WWTPs were driven dominantly by wastewater and operational variables, altitude was also an important variable influencing the quantitative relationships and community structures of nitrogen-removal bacteria in WWTPs particularly above 1500masl.
authors.affiliation: Ministry of Education Key laboratory of integrated regulation and resource development on shallow lakes, College of Environment, Hohai University, Nanjing 210098, PR China.
authors.forename: Lihua
authors.initials: L
authors.lastname: Niu
authors.affiliation: Ministry of Education Key laboratory of integrated regulation and resource development on shallow lakes, College of Environment, Hohai University, Nanjing 210098, PR China. Electronic address: envly@hhu.edu.cn.
authors.forename: Yi
authors.initials: Y
authors.lastname: Li
authors.affiliation: Ministry of Education Key laboratory of integrated regulation and resource development on shallow lakes, College of Environment, Hohai University, Nanjing 210098, PR China.
authors.forename: Peifang
authors.initials: P
authors.lastname: Wang
authors.affiliation: Ministry of Education Key laboratory of integrated regulation and resource development on shallow lakes, College of Environment, Hohai University, Nanjing 210098, PR China.
authors.forename: Wenlong
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Ministry of Education Key laboratory of integrated regulation and resource development on shallow lakes, College of Environment, Hohai University, Nanjing 210098, PR China.
authors.forename: Chao
authors.initials: C
authors.lastname: Wang
authors.affiliation: Ministry of Education Key laboratory of integrated regulation and resource development on shallow lakes, College of Environment, Hohai University, Nanjing 210098, PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Cai
authors.affiliation: Ministry of Education Key laboratory of integrated regulation and resource development on shallow lakes, College of Environment, Hohai University, Nanjing 210098, PR China.
authors.forename: Linqiong
authors.initials: L
authors.lastname: Wang
mesh_terms: D020562:Betaproteobacteria / Q000502:physiology; D002681:China; D009572:Nitrite Reductases / Q000378:metabolism; D009584:Nitrogen / Q000032:analysis / Q000378:metabolism*; D014865:Waste Disposal, Fluid; D062065:Wastewater / Q000382:microbiology*; D014871:Water Microbiology; D014873:Water Pollutants / Q000032:analysis / Q000378:metabolism*
chemical_list: D009572:Nitrite Reductases; D009584:Nitrogen; D062065:Wastewater; D014873:Water Pollutants; C052695:nitrite reductase, copper-containing
keywords: Activated sludge; Altitude; Ammonia-oxidizing bacteria; Nitrite-reducing bacteria; Nitrogen removal; Wastewater treatment plants