title: New anaerobic, ammonium-oxidizing community enriched from peat soil.
abstract: Anaerobic ammonium-oxidizing (anammox) bacteria have been recognized as an important sink for fixed nitrogen and are detected in many natural environments. However, their presence in terrestrial ecosystems has long been overlooked, and their contribution to the nitrogen cycling in natural and agricultural soils is currently unknown. Here we describe the enrichment and characterization of anammox bacteria from a nitrogen-loaded peat soil. After 8 months of incubation with the natural surface water of the sampling site and increasing ammonium and nitrite concentrations, anammox cells constituted 40 to 50% of the enrichment culture. The two dominant anammox phylotypes were affiliated with "Candidatus Jettenia asiatica" and "Candidatus Brocadia fulgida." The enrichment culture converted NH(4)(+) and NO(2)(-) to N(2) with the previously reported stoichiometry (1:1.27) and had a maximum specific anaerobic ammonium oxidation rate of 0.94 mmol NH(4)(+)·g (dry weight)(-1)·h(-1) at pH 7.1 and 32°C. The diagnostic anammox-specific lipids were detected at a concentration of 650 ng·g (dry weight)(-1), and pentyl-[3]-ladderane was the most abundant ladderane lipid.
authors.affiliation: Department of Environmental Engineering, Zhejiang University, Hangzhou 310029, China.
authors.forename: Bao-lan
authors.initials: BL
authors.lastname: Hu
authors.forename: Darci
authors.initials: D
authors.lastname: Rush
authors.forename: Erwin
authors.initials: E
authors.lastname: van der Biezen
authors.forename: Ping
authors.initials: P
authors.lastname: Zheng
authors.forename: Mark
authors.initials: M
authors.lastname: van Mullekom
authors.forename: Stefan
authors.initials: S
authors.lastname: Schouten
authors.forename: Jaap S
authors.initials: JS
authors.lastname: Sinninghe Damsté
authors.forename: Alfons J P
authors.initials: AJ
authors.lastname: Smolders
authors.forename: Mike S M
authors.initials: MS
authors.lastname: Jetten
authors.forename: Boran
authors.initials: B
authors.lastname: Kartal
mesh_terms: D001421:Bacteria, Anaerobic / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification / Q000502:physiology; D001431:Bacteriological Techniques; D003470:Culture Media; D017753:Ecosystem; D017404:In Situ Hybridization, Fluorescence; D008055:Lipids / Q000032:analysis; D008969:Molecular Sequence Data; D009426:Netherlands; D009573:Nitrites / Q000378:metabolism; D010084:Oxidation-Reduction; D000644:Quaternary Ammonium Compounds / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology; D013045:Species Specificity
chemical_list: D003470:Culture Media; D008055:Lipids; D009573:Nitrites; D000644:Quaternary Ammonium Compounds; D012336:RNA, Ribosomal, 16S