A novel strictly anaerobic, vancomycin-resistant, Gram-positive coccus (strain CCRI-16110T) was isolated from a human faecal specimen. This strain was characterized using morphological, biochemical and molecular taxonomic methods. The organism was unable to hydrolyse aesculin and failed to produce acid from cellobiose, d-lactose and α-raffinose. Acetic acid was the sole product of glucose fermentation by the organism. On the basis of 16S rRNA and tuf gene sequence comparison, strain CCRI-16110T was most closely related to species of the genus Ruminococcus and formed a hitherto unknown sublineage within the Clostridium coccoides rRNA cluster of organisms (cluster XIVa). Based on phenotypic and phylogenetic evidence, a novel species, Ruminococcus gauvreauii sp. nov., is proposed. The type strain is CCRI-16110T (=NML 060141T =CCUG 54292T =JCM 14987T).
A novel obligately anaerobic, alkalithermophilic, chemo-organotrophic bacterium was isolated from a small and very shallow geothermally heated pool at Pushino (Kamchatka, Far East Russia). The bacterium, designated strain JW/VK-KS5YT, was a Gram staining negative, Gram type positive rod. The cells were sometimes branched, with a tendency to grow in long chains, and were non-sporulating and non-motile. The shortest observed doubling time was 28 min when the novel strain was grown at 54–60 °C in 120 mM sodium carbonate-containing medium at pH25 °C 8.5–9.0. The novel bacterium grew on yeast extract and soytone as sole carbon and energy sources but could also use fumarate, thiosulfate and sulfur as electron acceptors. The DNA G+C content was 32.5 mol%. Based on phylogenetic, DNA–DNA hybridization and phenotypic data, it was concluded that isolate JW/VK-KS5YT (=VKM B-2436T=DSM 18970T) represents the type strain of a novel species, Anaerobranca zavarzinii sp. nov.
Five novel strains (2002T, 2902, 2006, 108T and 117) of cellulose-degrading, anaerobic, thermophilic bacteria were isolated from terrestrial hot springs of Kamchatka (Far East, Russia). Strains 2002T and 108T were non-spore-forming bacteria with a Gram-positive type cell wall and peritrichous flagella. Optimum growth of strains 2002T and 108T occurred at pH 7.0 and at temperatures of 70 and 65 °C, respectively. The G+C contents of the DNA of strains 2002T and 108T were 35.1 and 36.4 mol%, respectively. Comparative 16S rRNA gene sequence analysis revealed that the isolates belonged to the genus Caldicellulosiruptor. However, DNA–DNA hybridization experiments indicated that the levels of relatedness between strains 2002T and 108T and those of recognized members of the genus Caldicellulosiruptor ranged between 32 and 54 %. Based on both phenotypic and genomic differences, strains 2002T and 108T are considered to represent two novel species of the genus Caldicellulosiruptor. The names proposed for these organisms are Caldicellulosiruptor kronotskyensis sp. nov. (type strain 2002T=DSM 18902T=VKM B-2412T) and Caldicellulosiruptor hydrothermalis sp. nov. (type strain 108T=DSM 18901T=VKM B-2411T).
A Gram-positive, aerobic, rod-shaped bacterium (strain Eur1 9.5T) was isolated from a 9-m-deep permafrost sample from the Canadian high Arctic. Strain Eur1 9.5T could not be cultivated in liquid medium and grew over the temperature range 5–37 °C; no growth was observed at 42 °C and only slow growth was observed at 5 °C following 1 month of incubation. Eur1 9.5T grew over the pH range 5.5–8.9 and tolerated NaCl concentrations of 0–0.5 % (w/v). Eur1 9.5T grew heterotrophically on complex carbon substrates and chemolithoautotrophically on inorganic sulfur compounds, as demonstrated by growth on sodium thiosulfate and sulfite as sole electron donors. Eur1 9.5T contained iso-C15 : 0 as the major cellular fatty acid and menaquinone 7 (MK-7) as the major respiratory quinone. The cell-wall peptidoglycan was of type A1γ. The DNA G+C content was 53.1 mol%. The 16S rRNA gene sequence of strain Eur1 9.5T was only distantly related (≤87 % sequence similarity over 1407 bp) to any recognized bacterial species. Based on physiological and phylogenetic analyses, strain Eur1 9.5T is suggested to represent a novel species of a new genus, for which the name Tumebacillus permanentifrigoris gen. nov., sp. nov. is proposed. The type strain of Tumebacillus permanentifrigoris is Eur1 9.5T (=DSM 18773T =JCM 14557T).