Enrichment and characterization of an anammox bact

Enrichment and characterization of an anammox bacterium from a rotating biological contactor treating ammonium-rich leachateAbstractAnaerobicammoniumoxidationwithnitritetoN2(anammox)isarecentlydiscoveredmicrobialreactionwithinterestingpotentialfornitrogenremovalfromwastewater.Weenrichedananammoxculturefromaro-tatingdiskcontactor(nearKölliken,Switzerland)thatwasusedtotreatammonium-richleachatewithlowor-ganiccarboncontent.Thisenrichmentledtoarelativepopulationsizeof88%anammoxbacteria.Themicroor-ganismcarryingouttheanammoxreactionwasidentifiedbyanalysisofthe16SrDNAsequenceandbyfluores-cenceinsituhybridization(FISH)with16S-rRNA-target-ingprobes.Thepercentagesequenceidentitybetweenthe16SrDNAsequencesoftheKöllikenanammoxorganismandthearchetypeanammoxstrainCandidatusBrocadiaanammoxidanswas90.9%,butbetween98.5and98.9%withCandidatusKueneniastuttgartiensis,anorganismidentifiedinbiofilmsbymolecularmethods.TheKöl-likenculturecatalyzedtheanaerobicoxidationofammo-niumwithnitriteinamannerseeminglyide