A motile bacterium, designated strain TDA-040725-5T, was isolated from the haemolymph of a Chinese mitten crab, Eriocheir sinensis, with tremor disease. Based on 16S rRNA gene sequence analysis, the strain was phylogenetically distinct from other spiroplasmas but was closely related to Spiroplasma mirum ATCC 29335T. Cells of strain TDA-040725-5T were variable in length and shape, helical and motile, as determined by phase-contrast light microscopy. Examination by electron microscopy revealed wall-less cells delimited by a single membrane. The strain grew in M1D or R-2 liquid media at 20–40 °C, with optimum growth at 30 °C. Doubling time at the optimal temperature was 24 h. The strain catabolized glucose and hydrolysed arginine but did not hydrolyse urea. The DNA G+C content was 29.7±1 mol%. The genome size was ~1.4–1.6 Mbp. Serological analysis, performed using the deformation test, did not reveal any reciprocal titres ≥320, indicating that strain TDA-040725-5T had minimal cross-reactivity to strains of recognized species of the genus Spiroplasma. Based on this evidence, strain TDA-040725-5T ( = CCTCC M 207170T = DSM 21848T) represents a novel species of the genus Spiroplasma, for which the name Spiroplasma eriocheiris sp. nov. is proposed, belonging to the novel Spiroplasma serological group XLIII.
Two thermophilic, Gram-stain-positive, sporulating bacterial strains, which formed branched vegetative and aerial mycelia, were isolated from fallen leaves sampled from geothermal soils and designated ONI-1T and ONI-5T. Strain ONI-1T grew at 50–74 °C, with optimum growth at 60–65 °C, and strain ONI-5T grew at 45–74 °C, with optimum growth at 60–65 °C. The pH range for growth of the strains was pH 4.6–8.0, with optimum growth at pH 7.0. The DNA G+C contents of strains ONI-1T and ONI-5T were 60.2 and 58.1 mol%, respectively. The major fatty acid was iso-C17 : 0 and the major menaquinone was MK-9(H2). The cell walls of the strains contained glutamic acid, serine, glycine, histidine, alanine and ornithine. The polar lipids consisted of phosphatidylinositol, phosphatidylglycerol and a glycolipid. The cell-wall sugar was rhamnose. Detailed phylogenetic analysis based on 16S rRNA gene sequences indicated that the strains belong to the class Ktedonobacteria and that strains ONI-1T and ONI-5T are most closely related to Thermosporothrix hazakensis SK20-1T (85.3 and 84.5 % sequence similarity, respectively). 16S rRNA gene sequence similarity between the two strains was 96.6 %. Based on the phenotypic features and phylogenetic position, we propose that strains ONI-1T and ONI-5T constitute a novel genus containing two novel species, for which we propose the names Thermogemmatispora onikobensis gen. nov., sp. nov. (the type species; type strain ONI-1T = JCM 16817T = KCTC 19768T) and Thermogemmatispora foliorum sp. nov. (type strain ONI-5T = JCM 16818T = KCTC 19767T), within the new family Thermogemmatisporaceae fam. nov. and order Thermogemmatisporales ord. nov.