title: Simultaneous nitrite-dependent anaerobic methane and ammonium oxidation processes.
abstract: Nitrite-dependent anaerobic oxidation of methane (n-damo) and ammonium (anammox) are two recently discovered processes in the nitrogen cycle that are catalyzed by n-damo bacteria, including "Candidatus Methylomirabilis oxyfera," and anammox bacteria, respectively. The feasibility of coculturing anammox and n-damo bacteria is important for implementation in wastewater treatment systems that contain substantial amounts of both methane and ammonium. Here we tested this possible coexistence experimentally. To obtain such a coculture, ammonium was fed to a stable enrichment culture of n-damo bacteria that still contained some residual anammox bacteria. The ammonium supplied to the reactor was consumed rapidly and could be gradually increased from 1 to 20 mM/day. The enriched coculture was monitored by fluorescence in situ hybridization and 16S rRNA and pmoA gene clone libraries and activity measurements. After 161 days, a coculture with about equal amounts of n-damo and anammox bacteria was established that converted nitrite at a rate of 0.1 kg-N/m(3)/day (17.2 mmol day(-1)). This indicated that the application of such a coculture for nitrogen removal may be feasible in the near future.
authors.affiliation: Department of Microbiology, Institute for Water and Wetland Research, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.
authors.forename: Francisca A
authors.initials: FA
authors.lastname: Luesken
authors.forename: Jaime
authors.initials: J
authors.lastname: Sánchez
authors.forename: Theo A
authors.initials: TA
authors.lastname: van Alen
authors.forename: Janeth
authors.initials: J
authors.lastname: Sanabria
authors.forename: Huub J M
authors.initials: HJ
authors.lastname: Op den Camp
authors.forename: Mike S M
authors.initials: MS
authors.lastname: Jetten
authors.forename: Boran
authors.initials: B
authors.lastname: Kartal
mesh_terms: D000693:Anaerobiosis; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D019149:Bioreactors / Q000382:microbiology; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D017404:In Situ Hybridization, Fluorescence; D008697:Methane / Q000378:metabolism*; D008969:Molecular Sequence Data; D009573:Nitrites / Q000378:metabolism*; D010084:Oxidation-Reduction; D010802:Phylogeny; D000644:Quaternary Ammonium Compounds / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D014871:Water Microbiology; D018508:Water Purification / Q000379:methods
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D009573:Nitrites; D000644:Quaternary Ammonium Compounds; D012336:RNA, Ribosomal, 16S; D008697:Methane