title: Study on anaerobic ammonium oxidation process coupled with denitrification microbial fuel cells (MFCs) and its microbial community analysis.
abstract: Denitrifying MFC was successfully coupled with anaerobic ammonium oxidation process in this study. With the help of cathode electrons, the stoichiometry relationship Δ(-)NH3-N:Δ(-)NO2(-)-N:Δ(+)NO3(-)-N was approximate 1:1.37:0.03 during the stable operation, which demonstrated its further nitrite and nitrate reduction. According to microbial community analysis, Candidatus Brocadia sinica was the main anammox community, and Rhodopseudomonas palustris with electrochemical driven denitrifying ability, especially enriched in biofilm. Higher abundance of nirK genes in biofilm (compare to the control) and invariable amx genes in suspended sludge were responsible for its better nitrogen removal. The sludge and biofilm performed their own duties on anammox and denitrification, respectively, according to genes quantification. Under the totally autotrophic system, electron donors were "concentrated supplied" and easy to control, which avoided the suppression of anammox growth, making this autotrophic coupling process appears to be more promising.
authors.affiliation: Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China; State Key Engineering Research Center of Efficient Utilization of Water Resources and Engineering Safety, Hohai University, Nanjing 210098, China. Electronic address: lichao0609@163.com.
authors.forename: Chao
authors.initials: C
authors.lastname: Li
authors.affiliation: College of Environment, Nanjing University, Nanjing 210098, China.
authors.forename: Hongqiang
authors.initials: H
authors.lastname: Ren
authors.affiliation: College of Environment, Hohai University, Nanjing 210098, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Xu
authors.affiliation: Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China; State Key Engineering Research Center of Efficient Utilization of Water Resources and Engineering Safety, Hohai University, Nanjing 210098, China. Electronic address: caojiashun@hhu.edu.cn.
authors.forename: Jiashun
authors.initials: J
authors.lastname: Cao
mesh_terms: D064751:Ammonium Compounds / Q000737:chemistry / Q000378:metabolism*; D000693:Anaerobiosis; D052818:Autotrophic Processes; D001419:Bacteria / Q000378:metabolism; D001674:Bioelectric Energy Sources; D018441:Biofilms; D019149:Bioreactors / Q000382:microbiology; D058440:Denitrification; D004566:Electrodes; D009566:Nitrates / Q000032:analysis; D009573:Nitrites / Q000378:metabolism; D009584:Nitrogen / Q000032:analysis; D010084:Oxidation-Reduction; D012722:Sewage / Q000737:chemistry / Q000382:microbiology*
chemical_list: D064751:Ammonium Compounds; D009566:Nitrates; D009573:Nitrites; D012722:Sewage; D009584:Nitrogen
keywords: Anammox; Autotrophic denitrification; Biofilm; Microbial community