title: Physiological characterization of anaerobic ammonium oxidizing bacterium 'Candidatus Jettenia caeni'.
abstract: To date, six candidate genera of anaerobic ammonium-oxidizing (anammox) bacteria have been identified, and numerous studies have been conducted to understand their ecophysiology. In this study, we examined the physiological characteristics of an anammox bacterium in the genus 'Candidatus Jettenia'. Planctomycete KSU-1 was found to be a mesophilic (20-42.5°C) and neutrophilic (pH 6.5-8.5) bacterium with a maximum growth rate of 0.0020 h(-1) . Planctomycete KSU-1 cells showed typical physiological and structural features of anammox bacteria; i.e. (29) N2 gas production by coupling of (15) NH4 (+) and (14) NO2 (-) , accumulation of hydrazine with the consumption of hydroxylamine and the presence of anammoxosome. In addition, the cells were capable of respiratory ammonification with oxidation of acetate. Notably, the cells contained menaquinone-7 as a dominant respiratory quinone. Proteomic analysis was performed to examine underlying core metabolisms, and high expressions of hydrazine synthase, hydrazine dehydrogenase, hydroxylamine dehydrogenase, nitrite/nitrate oxidoreductase and carbon monoxide dehydrogenase/acetyl-CoA synthase were detected. These proteins require iron or copper as a metal cofactor, and both were dominant in planctomycete KSU-1 cells. On the basis of these experimental results, we proposed the name 'Ca. Jettenia caeni' sp. nov. for the bacterial clade of the planctomycete KSU-1.
authors.affiliation: Division of Environmental Engineering, Faculty of Engineering, Hokkaido University, North-13, West-8, Kita-ku, Sapporo, Hokkaido, 060-8628, Japan.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Ali
authors.affiliation: Department of Civil Engineering, Nagaoka National College of Technology, 888 Nishikatakaimachi, Nagaoka, Niigata, 940-0834, Japan.
authors.forename: Mamoru
authors.initials: M
authors.lastname: Oshiki
authors.affiliation: Department of Civil and Environmental Engineering, Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashihiroshima, Hiroshima, 739-8527, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Awata
authors.affiliation: Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Science, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Isobe
authors.affiliation: Biomass Refinery Research Center, National Institute of Advanced Industrial Science and Technology, 3-11-32, Kagamiyama, Higashihiroshima, Hiroshima, 739-0046, Japan.
authors.forename: Zenichiro
authors.initials: Z
authors.lastname: Kimura
authors.affiliation: Division of Environmental Engineering, Faculty of Engineering, Hokkaido University, North-13, West-8, Kita-ku, Sapporo, Hokkaido, 060-8628, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Yoshikawa
authors.affiliation: Department of Applied Life Science, Faculty of Biotechnology and Life Science, Sojo University, 4-22-1 Ikeda, Kumamoto, 860-0082, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Hira
authors.affiliation: Department of Civil and Environmental Engineering, Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashihiroshima, Hiroshima, 739-8527, Japan.
authors.forename: Tomonori
authors.initials: T
authors.lastname: Kindaichi
authors.affiliation: Division of Environmental Engineering, Faculty of Engineering, Hokkaido University, North-13, West-8, Kita-ku, Sapporo, Hokkaido, 060-8628, Japan.
authors.forename: Hisashi
authors.initials: H
authors.lastname: Satoh
authors.affiliation: Department of Applied Life Science, Faculty of Biotechnology and Life Science, Sojo University, 4-22-1 Ikeda, Kumamoto, 860-0082, Japan.
authors.forename: Takao
authors.initials: T
authors.lastname: Fujii
authors.affiliation: Division of Environmental Engineering, Faculty of Engineering, Hokkaido University, North-13, West-8, Kita-ku, Sapporo, Hokkaido, 060-8628, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Okabe
mesh_terms: D000085:Acetates / Q000378:metabolism; D000105:Acetyl Coenzyme A / Q000378:metabolism; D064751:Ammonium Compounds / Q000378:metabolism*; D001421:Bacteria, Anaerobic / Q000145:classification / Q000254:growth & development / Q000378:metabolism*; D006834:Hydrazines / Q000378:metabolism; D019811:Hydroxylamine / Q000378:metabolism; D009573:Nitrites / Q000378:metabolism; D010084:Oxidation-Reduction; D010802:Phylogeny; D040901:Proteomics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D024482:Vitamin K 2 / Q000031:analogs & derivatives / Q000378:metabolism
chemical_list: D000085:Acetates; D064751:Ammonium Compounds; D006834:Hydrazines; D009573:Nitrites; D012336:RNA, Ribosomal, 16S; D024482:Vitamin K 2; C029424:hydrazine; D019811:Hydroxylamine; D000105:Acetyl Coenzyme A; C062629:menaquinone 7