title: Characterization of a new marine nitrite oxidizing bacterium, Nitrospina watsonii sp. nov., a member of the newly proposed phylum "Nitrospinae".
abstract: Nitrite oxidizing bacteria are an integral part of the nitrogen cycle in marine waters, but the knowledge about their diversity is limited. Recently, a high abundance of Nitrospina-like 16S rRNA gene sequences has been detected in oceanic habitats with low oxygen content by molecular methods. Here, we describe a new strain of Nitrospina, which was sampled in 100m depth from the Black Sea. It coexisted with a not-yet cultivated chemoorganotrophic gammaproteobacterium and could be purified by classical isolation methods including Percoll density gradient centrifugation. The new Nitrospina-like bacterium grew lithoautotrophically at 28°C in diluted seawater supplemented with inorganic salts and nitrite. Gram-negative rods were characterized morphologically, physiologically and partly biochemically. The 16S rRNA gene of the new strain of Nitrospina is 97.9% similar to the described species N. gracilis and DNA/DNA hybridization experiments revealed a relatedness of 30.0%. The data from both Nitrospina species and environmental clones were used for an extensive 16S rRNA based phylogenetic study applying high quality filtering. Treeing analyses confirm the newly defined phylum status for "Nitrospinae" [18]. The results of phylogenetic and genotypic analyses support the proposal of a novel species Nitrospina watsonii sp. nov. (type strain 347(T), LMG 27401(T), NCIMB 14887(T)).
authors.affiliation: Biozentrum Klein Flottbek, Universität Hamburg, Mikrobiologie & Biotechnologie, Ohnhorststr. 18, D-22609 Hamburg, Germany. Electronic address: eva.spieck@uni-hamburg.de.
authors.forename: Eva
authors.initials: E
authors.lastname: Spieck
authors.affiliation: Biozentrum Klein Flottbek, Universität Hamburg, Mikrobiologie & Biotechnologie, Ohnhorststr. 18, D-22609 Hamburg, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Keuter
authors.affiliation: Biozentrum Klein Flottbek, Universität Hamburg, Mikrobiologie & Biotechnologie, Ohnhorststr. 18, D-22609 Hamburg, Germany.
authors.forename: Thilo
authors.initials: T
authors.lastname: Wenzel
authors.affiliation: Biozentrum Klein Flottbek, Universität Hamburg, Mikrobiologie & Biotechnologie, Ohnhorststr. 18, D-22609 Hamburg, Germany.
authors.forename: Eberhard
authors.initials: E
authors.lastname: Bock
authors.affiliation: Lehrstuhl für Mikrobiologie, TU München, Emil-Ramann-Str. 4, 85354 Freising, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Ludwig
mesh_terms: D052818:Autotrophic Processes; D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification*; D018407:Bacterial Physiological Phenomena; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D009573:Nitrites / Q000378:metabolism*; D010084:Oxidation-Reduction; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012492:Salts / Q000378:metabolism; D012623:Seawater / Q000382:microbiology*; D017422:Sequence Analysis, DNA; D013696:Temperature
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D009573:Nitrites; D012336:RNA, Ribosomal, 16S; D012492:Salts
keywords: Isolation; Marine nitrification; Nitrite oxidizing bacteria; Nitrospina; Phylogeny; Physiology