title: Isolates of 'Candidatus Nostocoida limicola' Blackall et al. 2000 should be described as three novel species of the genus Tetrasphaera, as Tetrasphaera jenkinsii sp. nov., Tetrasphaera vanveenii sp. nov. and Tetrasphaera veronensis sp. nov.
abstract: Despite differences in their morphologies, comparative analyses of 16S rRNA gene sequences revealed high levels of similarity (>94 %) between strains of the filamentous bacterium 'Candidatus Nostocoida limicola' and the cocci Tetrasphaera australiensis and Tetrasphaera japonica and the rod Tetrasphaera elongata, all isolated from activated sludge. These sequence data and their chemotaxonomic characters, including cell wall, menaquinone and lipid compositions and fingerprints of their 16S-23S rRNA intergenic regions, support the proposition that these isolates should be combined into a single genus containing six species, in the family Intrasporangiaceae in the Actinobacteria. This suggestion receives additional support from DNA-DNA hybridization data and when partial sequences of the rpoC1 gene are compared between these strains. Even though few phenotypic characterization data were obtained for these slowly growing isolates, it is proposed, on the basis of the extensive chemotaxonomic and molecular evidence presented here, that 'Candidatus N. limicola' strains Ben 17, Ben 18, Ben 67, Ben 68 and Ben 74 all be placed into the species Tetrasphaera jenkinsii sp. nov. (type strain Ben 74(T)=DSM 17519(T)=NCIMB 14128(T)), 'Candidatus N. limicola' strain Ben 70 into Tetrasphaera vanveenii sp. nov. (type strain Ben 70(T)=DSM 17518(T)=NCIMB 14127(T)) and 'Candidatus N. limicola' strains Ver 1 and Ver 2 into Tetrasphaera veronensis sp. nov. (type strain Ver 1(T)=DSM 17520(T)=NCIMB 14129(T)).
authors.affiliation: Biotechnology Research Centre, La Trobe University, Bendigo, Victoria 3552, Australia.
authors.forename: C M
authors.initials: CM
authors.lastname: McKenzie
authors.affiliation: Biotechnology Research Centre, La Trobe University, Bendigo, Victoria 3552, Australia.
authors.forename: E M
authors.initials: EM
authors.lastname: Seviour
authors.affiliation: DSMZ - Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH, Mascheroder Weg 1b, D-38124 Braunschweig, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Schumann
authors.affiliation: Biotechnology Research Centre, La Trobe University, Bendigo, Victoria 3552, Australia.
authors.forename: A M
authors.initials: AM
authors.lastname: Maszenan
authors.affiliation: Biotechnology Research Centre, La Trobe University, Bendigo, Victoria 3552, Australia.
authors.forename: J-R
authors.initials: JR
authors.lastname: Liu
authors.affiliation: Centre for Microscopy and Microanalysis, Department of Microbiology, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia.
authors.forename: R I
authors.initials: RI
authors.lastname: Webb
authors.affiliation: Australian Water Quality Centre, Bolivar, South Australia 5108, Australia.
authors.forename: P
authors.initials: P
authors.lastname: Monis
authors.affiliation: Australian Water Quality Centre, Bolivar, South Australia 5108, Australia.
authors.forename: C P
authors.initials: CP
authors.lastname: Saint
authors.affiliation: DSMZ - Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH, Mascheroder Weg 1b, D-38124 Braunschweig, Germany.
authors.forename: U
authors.initials: U
authors.lastname: Steiner
authors.affiliation: Biotechnology Research Centre, La Trobe University, Bendigo, Victoria 3552, Australia.
authors.forename: R J
authors.initials: RJ
authors.lastname: Seviour
mesh_terms: D039903:Actinobacteria / Q000737:chemistry / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D000192:Actinomycetales / Q000737:chemistry / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D015373:Bacterial Typing Techniques; D004269:DNA, Bacterial / Q000032:analysis; D021903:DNA, Ribosomal Spacer / Q000032:analysis; D020459:Genes, rRNA; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012338:RNA, Ribosomal, 23S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012722:Sewage / Q000382:microbiology; D013045:Species Specificity
chemical_list: D004269:DNA, Bacterial; D021903:DNA, Ribosomal Spacer; D012336:RNA, Ribosomal, 16S; D012338:RNA, Ribosomal, 23S; D012722:Sewage