title: Elucidation of major contributors involved in nitrogen removal and transcription level of nitrogen-cycling genes in activated sludge from WWTPs.
abstract: We investigated nitrogen-cycle bacterial communities in activated sludge from 8 municipal wastewater treatment plants (WWTPs). Redundancy analyses (RDA) showed that temperature was the most significant driving force in shaping microbial community structure, followed by influent NH4+and total nitrogen (TN). The diversity of ammonia oxidizing and nitrite reducing bacteria were investigated by the construction of amoA, nirS and nirK gene clone libraries. Phylogenetic analysis indicated that Thauera and Mesorhizobium were the predominant nitrite reducing bacteria, and Nitrosomonas was the only detected ammonia oxidizing bacteria in all samples. Quantification of transcription level of nirS and nirK genes indicated that nirS-type nitrite reducing bacteria played the dominant roles in nitrite reduction process. Transcription level of nirS gene positively correlated with influent NH4+and TN significantly, whereas inversely linked with hydraulic retention time. Temperature had a strong positive correlation to transcription level of amoA gene. Overall, this study deepened our understanding of the major types of ammonia oxidizing and nitrite reducing bacteria in activated sludge of municipal WWTPs. The relationship between transcription level of nitrogen-cycle genes and operational or environmental variables of WWTPs revealed in this work could provide guidance for optimization of operating parameters and improving the performance of nitrogen removal.
authors.affiliation: Key Laboratory of Molecular Microbiology and Technology for Ministry of Education, Nankai University, Tianjin, 300071, China.
authors.forename: You
authors.initials: Y
authors.lastname: Che
authors.affiliation: Key Laboratory of Molecular Microbiology and Technology for Ministry of Education, Nankai University, Tianjin, 300071, China.
authors.forename: Peixin
authors.initials: P
authors.lastname: Liang
authors.affiliation: Key Laboratory of Molecular Microbiology and Technology for Ministry of Education, Nankai University, Tianjin, 300071, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Gong
authors.affiliation: School of Life Science, Liaoning University, Shenyang, 110036, China.
authors.forename: Xiangyu
authors.initials: X
authors.lastname: Cao
authors.affiliation: Department of Biological Science, Jining Medical University, Jining, 272067, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Molecular Microbiology and Technology for Ministry of Education, Nankai University, Tianjin, 300071, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Yang
authors.affiliation: Key Laboratory of Molecular Microbiology and Technology for Ministry of Education, Nankai University, Tianjin, 300071, China.|Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, 300071, China.
authors.forename: Cunjiang
authors.initials: C
authors.lastname: Song
mesh_terms: D000641:Ammonia / Q000378:metabolism; D001419:Bacteria / Q000235:genetics; D044822:Biodiversity; D058440:Denitrification / Q000235:genetics; D005798:Genes, Bacterial; D016013:Likelihood Functions; D009573:Nitrites / Q000378:metabolism; D009584:Nitrogen / Q000302:isolation & purification*; D058458:Nitrogen Cycle / Q000235:genetics*; D010084:Oxidation-Reduction; D010802:Phylogeny; D012722:Sewage / Q000382:microbiology*; D014158:Transcription, Genetic; D062065:Wastewater / Q000382:microbiology*; D018508:Water Purification
chemical_list: D000641:Ammonia; D009573:Nitrites; D009584:Nitrogen; D012722:Sewage; D062065:Wastewater