title: Ammonia-oxidizing bacteria and archaea in groundwater treatment and drinking water distribution systems.
abstract: The ammonia-oxidizing prokaryote (AOP) community in three groundwater treatment plants and connected distribution systems was analyzed by quantitative real-time PCR and sequence analysis targeting the amoA gene of ammonia-oxidizing bacteria (AOB) and archaea (AOA). Results demonstrated that AOB and AOA numbers increased during biological filtration of ammonia-rich anoxic groundwater, and AOP were responsible for ammonium removal during treatment. In one of the treatment trains at plant C, ammonia removal correlated significantly with AOA numbers but not with AOB numbers. Thus, AOA were responsible for ammonia removal in water treatment at one of the studied plants. Furthermore, an observed negative correlation between the dissolved organic carbon (DOC) concentration in the water and AOA numbers suggests that high DOC levels might reduce growth of AOA. AOP entered the distribution system in numbers ranging from 1.5 x 10(3) to 6.5 x 10(4) AOPs ml(-1). These numbers did not change during transport in the distribution system despite the absence of a disinfectant residual. Thus, inactive AOP biomass does not seem to be degraded by heterotrophic microorganisms in the distribution system. We conclude from our results that AOA can be commonly present in distribution systems and groundwater treatment, where they can be responsible for the removal of ammonia.
authors.affiliation: KWR Watercycle Research Institute, P.O. Box 1072, 3430BB Nieuwegein, The Netherlands. paul.van.der.wielen@kwrwater.nl
authors.forename: Paul W J J
authors.initials: PW
authors.lastname: van der Wielen
authors.forename: Stefan
authors.initials: S
authors.lastname: Voost
authors.forename: Dick
authors.initials: D
authors.lastname: van der Kooij
mesh_terms: D000641:Ammonia / Q000378:metabolism*; D001105:Archaea / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D019843:Archaeal Proteins / Q000235:genetics; D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics; D016000:Cluster Analysis; D019641:DNA, Archaeal / Q000737:chemistry / Q000235:genetics; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid; D014871:Water Microbiology
chemical_list: D019843:Archaeal Proteins; D001426:Bacterial Proteins; D019641:DNA, Archaeal; D004269:DNA, Bacterial; D000641:Ammonia