A pink-red pigmented, non-motile, coccoid bacterial strain, ST0316T, was isolated from dust samples collected from the stratosphere in Japan. Phylogenetic analysis based on 16S rRNA gene sequences showed that it belonged to the genus Deinococcus. DNA G+C content (69.8 mol%), desiccation tolerance, and resistance to gamma-rays [D10 (dose required to reduce the bacterial population by 10-fold) >8 kGy] and UV radiation (D10 1000 J m−2) supported the affiliation of strain ST0316T to the genus Deinococcus. The major peptidoglycan amino acids were d-glutamic acid, glycine, d-alanine, l-alanine and ornithine. Predominant fatty acids were C16 : 1 ω7c, C16 : 0, C17 : 0 and iso-C17 : 0. Strain ST0316T diverged from recognized species of the genus Deinococcus, showing less than 93.0 % similarity values to its closest relatives Deinococcus apachensis, D. aerius, D. geothermalis and D. murrayi. Strain ST0316T also differed from the type strains of closely related species in its polar lipid profile, nitrate reduction and carbon-source assimilation tests. Therefore, we propose a new species of the genus Deinococcus, Deinococcus aetherius sp. nov. (type strain, ST0316T =JCM 11751T =DSM 21230T).
Two aerobic, Gram-negative, non-motile, non-sporulating, yellow-pigmented bacteria, strains TH92T and TH91, were isolated from a hot spring located in Laibin, Guangxi, in the south-eastern geothermal area of China. The isolates grew at 40–77 °C (optimally at 70 °C) and at pH 6.0–9.5 (optimally at pH 7.5–8.0). Phylogenetic analysis of 16S rRNA gene sequences and levels of DNA–DNA relatedness together indicated that the new isolates represented a novel species of the genus Thermus with closest affinity to Thermus aquaticus, Thermus igniterrae and Thermus thermophilus. Compared with their closest relatives, strains TH92T and TH91 were able to assimilate a wider range of carbohydrates, amino acids and organic acids as sole carbon sources for growth, such as lactose and melibiose. The new isolates had lower combined levels of C16 : 0 and iso-C16 : 0 compared with their closest relatives. On the basis of polyphasic taxonomic characterization, strains TH92T and TH91 are considered to represent a single novel species of the genus Thermus, for which the name Thermus arciformis sp. nov. is proposed. The type strain is TH92T (=CGMCC 1.6992T =JCM 15153T).
Two aerobic, non-motile and non-sporulating bacteria, strains LY1T and L462, were recovered from a hot spring located in the Qianshan area of north-eastern China. The novel strains had Gram-negative cell walls and grew at 30–66 °C (optimum 55–60 °C) and pH 5.5–10.0 (optimum pH 8.0–8.5). 16S rRNA gene sequence similarity analysis revealed that strains LY1T and L462 were most closely related to Meiothermus ruber ATCC 35948T, M. taiwanensis WR-30T and M. cerbereus GY-1T, with 97.1–98.4 % sequence similarity. Phylogenetic analysis indicated that the new isolates represented a novel species by forming a distinctive lineage within genus Meiothermus, which was confirmed by DNA–DNA reassociation values. Strain LY1T was obviously different from its closest relatives in a number of phenotypic characteristics, such as the inability to hydrolyse casein or to assimilate melibiose, trehalose, sucrose and lactose. Strain L462 was distinct in its ability to reduce nitrate. In addition, the novel strains were distinct in having larger amounts of anteiso-C17 : 0 than their closest phylogenetic neighbours. On the basis of this polyphasic taxonomic characterization, the name Meiothermus cateniformans sp. nov. is proposed for the novel species, currently represented by the type strain LY1T (=CGMCC 1.6990T =JCM 15151T) and strain L462 (=CGMCC 1.6989 =JCM 15150).
A mesophilic, strictly anaerobic, slightly halophilic bacterium, designated strain USBA 82T, was isolated from a terrestrial saline spring in the Colombian Andes. The non-spore-forming curved rods (5–7×1.3 μm) with pointed or rounded ends, stained Gram-negative and were motile by means of laterally inserted flagella. The strain grew optimally at 30 °C (growth range 20–40 °C), pH 7.3 (growth range pH 5.5–8.5) and 2 % (w/v) NaCl (growth range 0.1–7 % NaCl). The strain fermented peptides, amino acids and a few organic acids, but growth was not observed on carbohydrates, alcohols or fatty acids. The strain reduced thiosulfate and sulfur to sulfide. Sulfate, sulfite, nitrate and nitrite were not used as electron acceptors. On peptone alone, acetate, succinate, propionate and traces of ethanol were formed, but in the presence of thiosulfate, acetate and succinate were formed. The G+C content of the chromosomal DNA was 52 mol% (T m). 16S rRNA gene sequence analysis indicated that strain USBA 82T was affiliated to Dethiosulfovibrio peptidovorans within the phylum Synergistetes with a similarity value of approximately 93 %. Based on the differences between the new strain and the type species of the genus Dethiosulfovibrio, we suggest that strain USBA 82T represents a novel species of the genus for which the name Dethiosulfovibrio salsuginis sp. nov. is proposed. The type strain is USBA 82T (=DSM 21565T=KCTC 5659T).
A novel thermophilic, strictly anaerobic, heterotrophic bacterium, strain 2SM-2T, was isolated from the Shengli oilfield, China. This organism was identified as a member of the order Thermotogales on the basis of its 16S rRNA gene sequence and the presence of an external membranous toga-like structure. Cells stained Gram-negative, were non-motile, appeared as irregular cocci 0.7–0.9 μm in diameter, and occurred in clusters of two to six cells, with cells located within a ballooning toga-like membrane. Its optimum temperature, pH and NaCl concentration for growth were 65 °C, 7.0 and 15 g l−1, respectively. Under the optimum growth conditions, the doubling time was approximately 105 min. Strain 2SM-2T fermented a variety of simple and complex substrates such as glucose, acetate, methanol, starch and peptone while reducing elemental sulfur, sulfate and thiosulfate. The end products identified during growth on glucose were acetate, lactate, l-alanine, H2 and CO2. The DNA G+C content of this organism was 36.4 mol%. The results of 16S rRNA gene-based sequence comparisons revealed that the strain represented a new lineage within the family Thermotogaceae of the order Thermotogales. Based on the phenotypic and phylogenetic characteristics, it is proposed that this organism represents a novel species in a new genus within the family Thermotogaceae, for which the name Thermococcoides shengliensis gen. nov., sp. nov. is proposed. The type strain is 2SM-2T (=ACCC 00496T=DSM 22460T).