title: Occurrence of ammonia-oxidizing archaea in wastewater treatment plant bioreactors.
abstract: We report molecular evidence that ammonia-oxidizing archaea (AOA) occur in activated sludge bioreactors used to remove ammonia from wastewater. Using PCR primers targeting archaeal ammonia monooxygenase subunit A (amoA) genes, we retrieved and compared 75 sequences from five wastewater treatment plants operating with low dissolved oxygen levels and long retention times. All of these sequences showed similarity to sequences previously found in soil and sediments, and they were distributed primarily in four major phylogenetic clusters. One of these clusters contained virtually identical amoA sequences obtained from all five activated sludge samples (from Oregon, Wisconsin, Pennsylvania, and New Jersey) and accounted for 67% of all the sequences, suggesting that this AOA phylotype may be widespread in nitrifying bioreactors.
authors.affiliation: Environmental Engineering and Sciences Program, Stanford University, Stanford, CA 94305-2115, USA.
authors.forename: Hee-Deung
authors.initials: HD
authors.lastname: Park
authors.forename: George F
authors.initials: GF
authors.lastname: Wells
authors.forename: Hyokwan
authors.initials: H
authors.lastname: Bae
authors.forename: Craig S
authors.initials: CS
authors.lastname: Criddle
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Francis
mesh_terms: D000641:Ammonia / Q000378:metabolism*; D001105:Archaea / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D019149:Bioreactors; D019641:DNA, Archaeal / Q000032:analysis; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000235:genetics; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000379:methods; D017422:Sequence Analysis, DNA; D012722:Sewage / Q000382:microbiology*; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D019641:DNA, Archaeal; D012722:Sewage; D000641:Ammonia; D010088:Oxidoreductases; C045582:ammonia monooxygenase