Twenty-nine isolates of Lyme borreliosis (LB) group spirochaetes collected from ticks and rodents in China and Japan were included in a multilocus sequence analysis (MLSA). Using a different typing system, three of these strains had previously been identified as being divergent from other LB spirochaete species and the name ‘Borrelia yangtze’ sp. nov. was proposed. The data presented here confirm that the genetic distance, calculated using sequences of MLSA housekeeping genes, to other known LB group spirochaete species was < 95 % and to Borrelia valaisiana was 96.67 % (which represents the most closely related species within the group of LB spirochaetes). This and the fact that these strains are ecologically distinct from B. valaisiana (rodent-transmitted vs bird-transmitted) provide strong support for the validation of the proposed species status. We suggest the name Borrelia yangtzensis sp. nov. The type strain is Okinawa-CW62T ( = DSM 24625T = JCM 17189T).
A strain of free-living obligately anaerobic, halophilic spirochaete, SLT, was isolated from a sample of a cyanobacterial mat of the hypersaline Solar Lake, Sinai shore. The strain had motile helical cells, 0.35–0.40 × 6–10 μm. Strain SLT exhibited high resistance to NaCl among known halophilic spirochaetes growing at NaCl concentrations from 2 to 12 % (optimum growth at 7 %). The strain grew at temperatures from 10 to 32 °C (optimum at 28 °C) and pH from 6 to 8.5 (optimum at pH 7.0–7.5). Carbohydrates, but not alcohols, organic acids or nitrogenous compounds (peptone, yeast extract and amino acids), were used as energy substrates for growth. Ethanol, acetate, lactate, H2 and CO2 were the products of glucose fermentation. Sulfide was produced in the presence of S0 or thiosulfate in the medium. The DNA G+C content was 44.7 mol%. Based on 16S rRNA gene sequence analysis, strain SLT clustered within the genus Spirochaeta, exhibiting 94.2 and 93.7 % similarity with its closest relatives, Spirochaeta bajacaliforniensis DSM 160554T and Spirochaeta smaragdinae DSM 11293T, respectively; similarity with other species did not exceed 86 %. The phenotypic and chemotaxonomic characteristics of the strain, as well as the results of phylogenetic analysis support the classification of strain SLT as representing a novel species of the genus Spirochaeta, for which the name Spirochaeta sinaica sp. nov. is proposed. The type strain is SLT ( = DSM 14994 = UNIQEM U 783).
Five human clinical isolates of an unknown, strictly anaerobic, slow-growing, Gram-stain-negative, rod-shaped micro-organism were subjected to a polyphasic taxonomic study. Comparative 16S rRNA gene sequence-based phylogeny showed that the isolates grouped in a clade that included members of the genera Pyramidobacter, Jonquetella, and Dethiosulfovibrio; the type strain of Pyramidobacter piscolens was the closest relative with 91.5–91.7 % 16S rRNA gene sequence similarity. The novel strains were mainly asaccharolytic and unreactive in most conventional biochemical tests. Major metabolic end products in trypticase/glucose/yeast extract broth were acetic acid and propionic acid and the major cellular fatty acids were C13 : 0 and C16 : 0, each of which could be used to differentiate the strains from P. piscolens. The DNA G+C content based on whole genome sequencing for the reference strain 22-5-S 12D6FAA was 57 mol%. Based on these data, a new genus, Rarimicrobium gen. nov., is proposed with one novel species, Rarimicrobium hominis sp. nov., named after the exclusive and rare finding of the taxon in human samples. Rarimicrobium is the fifth genus of the 14 currently characterized in the phylum Synergistetes and the third one in subdivision B that includes human isolates. The type strain of Rarimicrobium hominis is ADV70T ( = LMG 28163T = CCUG 65426T).
A Gram-staining-negative, aerobic, non-motile, coccus-shaped bacterium, designated SAORIC-696T, was isolated from deep-sea water at a depth of 1700 m in the western North Pacific Ocean. Optimal growth of strain SAORIC-696T was observed at 15 °C, pH 7.0 and in the presence of 2 % (w/v) NaCl. Strain SAORIC-696T formed a robust phylogenetic clade with members of the genus Lentisphaera. The 16S rRNA gene sequence similarity showed that strain SAORIC-696T was most closely related to Lentisphaera marina (98.0 % similarity) and Lentisphaera araneosa (97.3 %). The DNA–DNA relatedness between SAORIC-696T and two species of the genus Lentisphaera was only 27–42 %. The DNA G+C content of strain SAORIC-696T was 43.1 mol% and predominant cellular fatty acids were C16 : 1ω9c (36.8 %), C14 : 0 (22.5 %) and C14 : 0 3-OH and/or iso-C16 : 1 I (10.8 %). Strain SAORIC-696T contained MK-7 as the only respiratory quinone. On the basis of taxonomic data collected in this study, it was concluded that strain SAORIC-696T represents a novel species of the genus Lentisphaera, for which the name Lentisphaera profundi sp. nov. is proposed, with the type strain SAORIC-696T ( = NBRC 110692T = KCTC 42681T).