title: Methanosarcina spelaei sp. nov., a methanogenic archaeon isolated from a floating biofilm of a subsurface sulphurous lake.
abstract: A novel methanogenic archaeon, strain MC-15(T), was isolated from a floating biofilm on a sulphurous subsurface lake in Movile Cave (Mangalia, Romania). Cells were non-motile sarcina-like cocci with a diameter of 2-4 µm, occurring in aggregates. The strain was able to grow autotrophically on H2/CO2. Additionally, acetate, methanol, monomethylamine, dimethylamine and trimethylamine were utilized, but not formate or dimethyl sulfide. Trypticase peptone and yeast extract were not required for growth. Optimal growth was observed at 33 °C, pH 6.5 and a salt concentration of 0.05 M NaCl. The predominant membrane lipids of MC-15(T) were archaeol and hydroxyarchaeol phosphatidylethanolamine, phosphatidylglycerol, and phosphatidylinositol as well as hydroxyarchaeol phosphatidylserine and archaeol glycosaminyl phosphatidylinositol. The closely related species, Methanosarcina vacuolata and Methanosarcina horonobensis, had a similar composition of major membrane lipids to strain MC-15(T). The 16S rRNA gene sequence of strain MC-15(T) was similar to those of Methanosarcina vacuolata DSM 1232(T) (sequence similarity 99.3%), Methanosarcina horonobensis HB-1(T) (98.8%), Methanosarcina barkeri DSM 800(T) (98.7%) and Methanosarcina siciliae T4/M(T) (98.4%). DNA-DNA hybridization revealed 43.3% relatedness between strain MC-15(T) and Methanosarcina vacuolata DSM 1232(T). The G+C content of the genomic DNA was 39.0 mol%. Based on physiological, phenotypic and genotypic differences, strain MC-15(T) represents a novel species of the genus Methanosarcina, for which the name Methanosarcina spelaei sp. nov. is proposed. The type strain is MC-15(T) ( = DSM 26047(T) = JCM 18469(T)).
authors: Finnish Forest Research Institute, Rovaniemi Unit, Eteläranta 55, 96100 Rovaniemi, Finland.
authors: Lars
authors: L
authors: Ganzert
authors: Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Research Unit Potsdam, Telegrafenberg A45, 14473 Potsdam, Germany.
authors: Janosch
authors: J
authors: Schirmack
authors: GFZ German Research Center for Geosciences, Section 4.5 Geomicrobiology, Telegrafenberg, Potsdam, Germany.
authors: Mashal
authors: M
authors: Alawi
authors: GFZ German Research Center for Geosciences, Section 4.3 Organic Geochemistry, Telegrafenberg, Potsdam, Germany.
authors: Kai
authors: K
authors: Mangelsdorf
authors: University of Duisburg-Essen, Biofilm Centre, Aquatic Biotechnology, Geibelstraße 41, 47057 Duisburg, Germany.
authors: Wolfgang
authors: W
authors: Sand
authors: Emil Racoviţă Institute of Speleology, Str. Frumoasă, nr. 31, sect. 1, Bucharest, Romania.
authors: Alexandra
authors: A
authors: Hillebrand-Voiculescu
authors: GFZ German Research Center for Geosciences, Section 4.5 Geomicrobiology, Telegrafenberg, Potsdam, Germany.
authors: Dirk
authors: D
authors: Wagner
mesh_terms: D001482:Base Composition; D018441:Biofilms; D059552:Caves / Q000382:microbiology; D019641:DNA, Archaeal / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D060106:Lakes / Q000382:microbiology; D008055:Lipids / Q000737:chemistry; D017020:Methanosarcina / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012383:Romania; D017422:Sequence Analysis, DNA; D013455:Sulfur; D014871:Water Microbiology
chemical_list: D019641:DNA, Archaeal; D004269:DNA, Bacterial; D008055:Lipids; D012336:RNA, Ribosomal, 16S; D013455:Sulfur