A novel moderately thermophilic, red-pigmented bacterium, designated strain AZM34c11T, was isolated from the bottom of a 1000 m-deep drilled well located in a Japanese hot spring. Cells were Gram-negative and grew optimally at 50 °C, at pH 7.6 and with 0–0.3 % (w/v) NaCl. Analysis of the 16S rRNA gene sequence revealed that the isolate belonged to the genus Meiothermus. Levels of 16S rRNA gene sequence similarity between strain AZM34c11T and the type strains of recognized Meiothermus species were 88.2–94.8 %. Strain AZM34c11T was distinguished from recognized Meiothermus species by its cellular fatty acid profile: iso-C16 : 0 was one of the predominant components and hydroxy fatty acids were present only in trace amounts. The strain could also be differentiated based on its growth substrate preferences and characteristic enzyme reactions. On the basis of these results, strain AZM34c11T is considered to represent a novel species of the genus Meiothermus, for which the name Meiothermus hypogaeus sp. nov. is proposed. The type strain is AZM34c11T ( = NBRC 106114T = DSM 23238T).
An aerobic, pink-pigmented, budding bacterium, designated strain S26T, was isolated from an acidic Sphagnum peat bog of north-western Russia. Cells were non-motile and spherical, occurring singly, in pairs or in short chains, and were able to attach to surfaces by means of a holdfast material. Strain S26T was a moderately acidophilic, mesophilic organism capable of growth at pH 3.2–7.1 (optimum at pH 4.8–5.0) and at 4–33 °C (optimum at 20–26 °C). Most sugars, several organic acids and polyalcohols were the preferred growth substrates. The major fatty acids were C16 : 0, C18 : 1ω9c and C18 : 2ω6c,12c. The major neutral lipids were n-C31 : 9 hydrocarbon and squalene; the polar lipids were phosphatidylglycerol, phosphatidylcholine and components with an unknown structure. The DNA G+C content of strain S26T was 62.2 mol%. 16S rRNA gene sequence analysis showed that strain S26T is a member of the order Planctomycetales. Among taxonomically characterized representatives of this order, highest levels of 16S rRNA gene sequence similarity (95.1–95.2 %) were observed with strains of the non-filamentous, peat-inhabiting planctomycete Singulisphaera acidiphila. Strain S26T could be differentiated from Singulisphaera acidiphila based on pigmentation, significant differences in substrate utilization patterns, greater tolerance of acidic conditions and the presence of C16 : 1ω9c. Based on the data presented, strain S26T is considered to represent a novel species of the genus Singulisphaera, for which the name Singulisphaera rosea sp. nov. is proposed; the type strain is S26T ( = DSM 23044T = VKM B-2599T).
Free-living bacteria with spherical cells 0.5–2.5 µm in diameter were isolated from freshwater sediment. 16S rRNA gene sequence analysis placed the new isolates within the phylum Spirochaetes (‘spirochaetes’). The isolates never displayed a helical morphology or motility. Growth occurred in the presence of 100 mg ampicillin l−1 in complex and defined mineral salts medium amended with vitamins, yeast extract and monosaccharides, disaccharides or soluble starch as fermentable substrates. Two distinct isolates, designated BuddyT and GrapesT, exhibited doubling times of 21±2 and 15±1 h in glucose-amended medium and grew at 15–37 and 15–30 °C. Optimum growth was observed between 25 and 30 °C and pH 6.5–7.5, with no growth below pH 5 or above pH 10. Hexose and pentose fermentation yielded ethanol, acetate and formate as major end products. Growth was strictly fermentative and anaerobic, but the isolates tolerated brief oxygen exposure. Nitrate, sulfate, thiosulfate and carbon dioxide were not used as electron acceptors, but soluble Fe(III) was reduced to Fe(II) in glucose-amended medium. The DNA G+C base contents of isolates BuddyT and GrapesT were 45.5–46.4 and 47.0–49.2 mol%, respectively. Phospholipid fatty acid (PLFA) profiles contained large proportions of C14 : 0 and C16 : 0 straight-chain saturated fatty acids; C16 : 1ω7c and C16 : 1ω9c dominated the mono-unsaturated PLFAs in isolate GrapesT, whereas isolate BuddyT also possessed C18 : 1ω5c, C18 : 1ω7c and C18 : 1ω9c fatty acids. Branched monoenoic acids accounted for up to 12.4 and 30 % of the total PLFA in isolates GrapesT and BuddyT, respectively. Based on their unique morphological features and the phylogenetic distance from their closest relatives, we propose the new genus, Sphaerochaeta gen. nov., to accommodate the new isolates within the novel species Sphaerochaeta globosa sp. nov. (type strain BuddyT = DSM 22777T = ATCC BAA-1886T) and Sphaerochaeta pleomorpha sp. nov. (type strain GrapesT = DSM 22778T = ATCC BAA-1885T). Sphaerochaeta globosa is the type species of the genus.
Bacterial strain TM-1T was isolated from the gut of a wood-feeding termite, Reticulitermes chinensis Snyder. Cells of strain TM-1T were Gram-negative, spherical (1.0–2.0 µm in diameter), non-motile, non-sporulating and red-pigmented. Strain TM-1T was resistant to UV radiation, showing 34 % survival after exposure to UV light at a dose of 100 J m−2. Growth occurred at 20–40 °C (optimum, 30 °C), at pH 6.0–10.0 (optimum, pH 6.0–7.0), and in the presence of 0–1 % (w/v) NaCl (optimum, 0–0.4 %). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain TM-1T was related to members of the genus Deinococcus, with sequence similarities ranging from 87.0 to 94.0 %. The peptidoglycan of strain TM-1T contained ornithine, alanine, glycine and glutamic acid. The most abundant cellular fatty acids of strain TM-1T were summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c; 22.3 %) and C16 : 0 (37.5 %). MK-8 was the predominant quinone. The polar lipid profile contained three glycophospholipids, six glycolipids, one aminolipid and three unknown lipids. DNA of the type strain had a G+C content of 65.6 mol%. Based on the phylogenetic, chemotaxonomic and phenotypic data presented, strain TM-1T represents a novel species of the genus Deinococcus, for which the name Deinococcus reticulitermitis sp. nov. is proposed, with TM-1T ( = CGMCC 1.10218T = NBRC 106334T) as the type strain.