title: Polynucleobacter cosmopolitanus sp. nov., free-living planktonic bacteria inhabiting freshwater lakes and rivers.
abstract: Five heterotrophic, aerobic, catalase- and oxidase-positive, non-motile strains were characterized from freshwater habitats located in Austria, France, Uganda, P. R. China and New Zealand. The strains shared 16S rRNA gene similarities of >/=99.3 %. The novel strains grew on NSY medium over a temperature range of 10-35 degrees C (two strains also grew at 5 degrees C and one strain grew at 38 degrees C) and a NaCl tolerance range of 0.0-0.3 % (four strains grew up to 0.5 % NaCl). The predominant fatty acids were C(16 : 0), C(18 : 1)omega7c, C(12 : 0) 3-OH, and summed feature 3 (including C(16 : 1)omega7c). The DNA G+C content of strain MWH-MoIso2(T) was 44.9 mol%. Phylogenetic analysis of 16S rRNA gene sequences demonstrated that the five new strains formed a monophyletic cluster closely related to Polynucleobacter necessarius (96-97 % sequence similarity). This cluster also harboured other isolates as well as environmental sequences which have been obtained from several habitats. Investigations with taxon-specific FISH probes demonstrated that the novel bacteria dwell as free-living, planktonic cells in freshwater systems. Based on the revealed phylogeny and pronounced chemotaxonomic differences to P. necessarius (presence of >7 % C(12 : 0) 3-OH and absence of C(12 : 0) and C(12 : 0) 2-OH), the new strains are suggested to represent a novel species, for which the name Polynucleobacter cosmopolitanus sp. nov. is proposed. The type strain is MWH-MoIso2(T) (=DSM 21490(T)=CIP 109840(T)=LMG 25212(T)). The novel species belongs to the minority of described species of free-living bacteria for which both in situ data from their natural environments and culture-based knowledge are available.
authors: Institute for Limnology, Austrian Academy of Sciences, Mondseestrasse 9, 5310 Mondsee, Austria.
authors: Martin W
authors: MW
authors: Hahn
authors: DSMZ - Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH, Inhoffenstraße 7B, D-38124 Braunschweig, Germany.
authors: Elke
authors: E
authors: Lang
authors: Institute for Limnology, Austrian Academy of Sciences, Mondseestrasse 9, 5310 Mondsee, Austria.
authors: Ulrike
authors: U
authors: Brandt
authors: Helmholtz Center for Infection Research (formerly GBF), Electron Microscopy Laboratory, Inhoffenstraße 7B, D-38124 Braunschweig, Germany.
authors: Heinrich
authors: H
authors: Lünsdorf
authors: State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, East Beijing Road 73, Nanjing 210008, PR China.|Institute for Limnology, Austrian Academy of Sciences, Mondseestrasse 9, 5310 Mondsee, Austria.
authors: Qinglong L
authors: QL
authors: Wu
authors: DSMZ - Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH, Inhoffenstraße 7B, D-38124 Braunschweig, Germany.
authors: Erko
authors: E
authors: Stackebrandt
mesh_terms: D001482:Base Composition; D042521:Burkholderiaceae / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D004269:DNA, Bacterial / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D005227:Fatty Acids / Q000378:metabolism; D005618:Fresh Water / Q000382:microbiology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D010933:Plankton / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D005227:Fatty Acids; D012336:RNA, Ribosomal, 16S