title: Anammox organisms: enrichment, cultivation, and environmental analysis.
abstract: Anaerobic ammonium oxidation (anammox) is the microbial oxidation of ammonium with nitrite to dinitrogen gas under strict anoxic conditions mediated by planctomycete-like bacteria. Anammox is not only important in the oceanic nitrogen cycle, but can also contribute substantially to nitrogen removal in municipal and industrial wastewater treatment. This chapter addresses the enrichment and cultivation of anammox bacteria in a sequencing batch reactor (SBR) and a gas lift reactor. The reactors can be operated anoxically as an anammox reactor or as an oxygen-limited "completely autotrophic nitrogen removal over nitrite" (CANON) system. Pure cultures of anammox organisms have not yet been obtained, but anammox cells can be purified to more than 99.5% using a Percoll density gradient centrifugation protocol. Furthermore, we show how anammox communities in natural and man-made ecosystems can be identified and characterized using molecular methods such as fluorescence in situ hybridization (FISH) or Planctomycetes/anammox-specific polymerase chain reaction (PCR). Both techniques are based on retrieved 16S rRNA gene sequences. In addition to 16S rRNA, unique anammox ladderane lipids can also serve as biomarkers to determine the abundance of anammox organisms in environmental samples.
authors.affiliation: Department of Microbiology, Institute for Water & Wetland Research, Radboud University Nijmegen, The Netherlands.
authors.forename: Mike
authors.initials: M
authors.lastname: Jetten
authors.forename: Markus
authors.initials: M
authors.lastname: Schmid
authors.forename: Katinka
authors.initials: K
authors.lastname: van de Pas-Schoonen
authors.forename: Jaap
authors.initials: J
authors.lastname: Sinninghe Damsté
authors.forename: Marc
authors.initials: M
authors.lastname: Strous
mesh_terms: D000693:Anaerobiosis; D001421:Bacteria, Anaerobic / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification*; D019149:Bioreactors; D002499:Centrifugation, Density Gradient; D017404:In Situ Hybridization, Fluorescence / Q000379:methods; D008563:Membrane Lipids / Q000032:analysis; D009573:Nitrites / Q000378:metabolism; D010084:Oxidation-Reduction; D016133:Polymerase Chain Reaction; D000644:Quaternary Ammonium Compounds / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012722:Sewage / Q000382:microbiology; D014871:Water Microbiology
chemical_list: D008563:Membrane Lipids; D009573:Nitrites; D000644:Quaternary Ammonium Compounds; D012336:RNA, Ribosomal, 16S; D012722:Sewage