title: Distribution and diversity of anaerobic ammonium oxidation (anammox) bacteria in the sediment of a eutrophic freshwater lake, Lake Kitaura, Japan.
abstract: Although the emission of N(2) via anaerobic ammonium oxidation (anammox) is a key process in the elimination of nitrogenous compounds from aquatic environments, little information is available regarding its significance and the relevant microorganisms (anammox bacteria) in eutrophic freshwater lakes. In the present study, the anammox bacteria in the sediment of a eutrophic lake in Japan, Lake Kitaura, were examined using a (15)N-tracer technique to measure their potential anammox activity. Potential anammox activity was localized to the northern region of the lake where a stable supply of both NH(4)(+) and NO(3)(-) existed in the sediment. These results suggest the contribution of anammox bacteria to the total emission of N(2) from sediment in this eutrophic lake to not be negligible. Moreover, selective PCR successfully amplified anammox bacteria-related (Brocadiales-related) 16S rRNA genes from sediment samples in which potential anammox activity was observed. The clone libraries consisted of diverse phylotypes except the genus "Scalindua"-lineages, and the lineages of genus "Brocadia" were dominantly recovered, followed by the genus "Kuenenia"-lineages. Most of them, however, were novel and phylogenetically distinguishable from known Brocadiales species. A unique population of anammox bacteria inhabits and potentially contributes to the emission of N(2) from Lake Kitaura.
authors.affiliation: Laboratory of Marine Microbiology, Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Japan.
authors.forename: Ikuo
authors.initials: I
authors.lastname: Yoshinaga
authors.forename: Teruki
authors.initials: T
authors.lastname: Amano
authors.forename: Takao
authors.initials: T
authors.lastname: Yamagishi
authors.forename: Kentaro
authors.initials: K
authors.lastname: Okada
authors.forename: Shingo
authors.initials: S
authors.lastname: Ueda
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Sako
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Suwa
mesh_terms: D001421:Bacteria, Anaerobic / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D044822:Biodiversity; D004269:DNA, Bacterial / Q000235:genetics; D019015:Geologic Sediments / Q000382:microbiology*; D007564:Japan; D060106:Lakes / Q000382:microbiology*; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010802:Phylogeny; D000644:Quaternary Ammonium Compounds; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D004269:DNA, Bacterial; D000644:Quaternary Ammonium Compounds; D012336:RNA, Ribosomal, 16S