title: Rectinema cohabitans gen. nov., sp. nov., a rod-shaped spirochaete isolated from an anaerobic naphthalene-degrading enrichment culture.
abstract: The anaerobic, non-motile strain HMT was isolated from the naphthalene-degrading, sulfate-reducing enrichment culture N47. For 20 years, strain HMT has been a stable member of culture N47 although it is neither able to degrade naphthalene nor able to reduce sulfate in pure culture. The highest similarity of the 16S rRNA gene sequence of strain HMT (89 %) is with a cultivated member of the family Spirochaetaceae, Treponema caldariumstrain H1T (=DSM 7334T), an obligately anaerobic, thermophilic spirochaete isolated from cyanobacterial mat samples collected at a freshwater hot spring in Oregon, USA. In contrast to this strain and the majority of spirochaete species described, strain HMT showed a rod-shaped morphology. Growth occurred at temperatures between 12 and 50 °C (optimum 37 °C) but the isolate was not able to grow at 60 °C. The strain fermented various sugars including d-glucose, d-fructose, lactose and sucrose. Addition of 0.1 % (w/v) yeast extract or 0.1 % (w/v) tryptone to the culture medium was essential for growth and could not be replaced by either the vitamin solutions tested or by 0.1 % (w/v) peptone or 0.1 % (w/v) casamino acids. The DNA G+C content of the isolate was 51.5 mol%. The major fatty acids were C14 : 0, C18 : 1ω13c, C16 : 1ω9t, C16 : 1ω11c and C16 : 1ω9c. Based on the unique morphology and the phylogenetic distance from the closest cultivated relative, a novel genus and species, Rectinema cohabitans gen. nov., sp. nov., is proposed. The type strain is strain HMT (=DSM 100378T=JCM 30982T).
authors.affiliation: Helmholtz Zentrum München, Institute of Groundwater Ecology, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany.|Universität Duisburg-Essen, Biofilm Centre, Universitätsstr. 5, 45141 Essen, Germany.
authors.forename: Janina S
authors.initials: JS
authors.lastname: Koelschbach
authors.affiliation: Helmholtz Zentrum München, Institute of Groundwater Ecology, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany.
authors.forename: Housna
authors.initials: H
authors.lastname: Mouttaki
authors.affiliation: Helmholtz Zentrum München, Institute of Groundwater Ecology, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany.
authors.forename: Carolin
authors.initials: C
authors.lastname: Pickl
authors.affiliation: Helmholtz Zentrum für Umweltforschung, Department of Environmental Biotechnology, Permoserstr. 15, 04318 Leipzig, Germany.
authors.forename: Hermann J
authors.initials: HJ
authors.lastname: Heipieper
authors.affiliation: Universität Regensburg, Zentrum für Elektronenmikroskopie der Fakultät für Biologie und Vorklinische Medizin, Universitätsstr. 31, 93053 Regensburg, Germany.
authors.forename: Reinhard
authors.initials: R
authors.lastname: Rachel
authors.affiliation: Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK 73019, USA.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Lawson
authors.affiliation: Universität Duisburg-Essen, Biofilm Centre, Universitätsstr. 5, 45141 Essen, Germany.
authors.forename: Rainer U
authors.initials: RU
authors.lastname: Meckenstock
mesh_terms: D000596:Amino Acids / Q000737:chemistry; D015373:Bacterial Typing Techniques; D001482:Base Composition; D004269:DNA, Bacterial / Q000235:genetics; D005227:Fatty Acids / Q000737:chemistry; D045482:Hot Springs / Q000382:microbiology*; D009922:Oregon; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D013142:Spirochaeta / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D013144:Spirochaetales / Q000235:genetics
chemical_list: D000596:Amino Acids; D004269:DNA, Bacterial; D005227:Fatty Acids; D012336:RNA, Ribosomal, 16S; C017721:casamino acids