The taxonomic positions of two gamma- and UV-ray-resistant strains isolated from radiation-polluted soil in north-west China were determined in a polyphasic study. The organisms, designated R12T and R13T, were Gram-stain-positive, non-spore-forming cocci, which contained MK-8 as the major respiratory quinone and C16 : 1 ω7c and C16 : 0 as major fatty acids. The cell walls of strains R12T and R13T contained ornithine. Phylogenetic analysis based on 16S rRNA gene sequences and DNA–DNA hybridizations showed that strains R12T and R13T are members of novel species belonging to the genus Deinococcus, with Deinococcus radiodurans DSM 20539T as the closest relative. The isolates R12T and R13T shared 97 and 97.1 % 16S rRNA gene similarity, respectively, and 29.5 and 33.3 % DNA–DNA relatedness, respectively, with D. radiodurans DSM 20539T. The DNA G+C contents of isolates R12T and R13T were 66.7 and 63.8 %, respectively. On the basis of phenotypic tests and other results, two species, Deinococcus wulumuqiensis sp. nov. (type strain R12T =CGMCC 1.8884T =NBRC 105665T) and Deinococcus xibeiensis sp. nov. (type strain R13T =CGMCC 1.8885T =NBRC 105666T), are proposed.
Twenty coagulase-negative Staphylococcus strains displaying α-haemolysis (δ-haemolysin) on sheep-blood agar were isolated from the noses of different pigs in Switzerland. The strains were Gram-stain-positive, non-motile cocci, catalase-positive and coagulase-negative. Sequence analysis of the 16S rRNA gene, sodA, rpoB, dnaJ and hsp60 and phylogenetic characteristics revealed that the strains showed the closest relatedness to Staphylococcus microti CCM 4903T and Staphylococcus muscae DSM 7068T. The strains can be differentiated from S. microti by the absence of mannose fermentation and arginine arylamidase and from S. muscae by the absence of β-glucuronidase activity and production of alkaline phosphatase. The chosen type strain ARI 262T shared 20.1 and 31.9 % DNA relatedness with S. microti DSM 22147T and S. muscae CCM 4903T, respectively, by DNA–DNA hybridization. iso-C15 : 0, anteiso-C15 : 0 and iso-C17 : 0 were the most common fatty acids. Cell-wall structure analysis revealed the peptidoglycan type A3α l-Lys–Gly2–l-Ser–Gly (type A11.3). The presence of teichoic acid was determined by sequencing the N-acetyl-β-d-mannosaminyltransferase gene tarA, which is involved in biosynthesis of ribitol teichoic acid. Menaquinone 7 (MK-7) was the predominant respiratory quinone. The G+C content of ARI 262T was 38.8 mol%. The isolated strains represent a novel species of the genus Staphylococcus, for which we propose the name Staphylococcus rostri sp. nov. The type strain is ARI 262T (=DSM 21968T =CCUG 57266T) and strain ARI 602 (=DSM 21969 =CCUG 57267) is a reference strain.
A novel thermophilic, strictly anaerobic, chemo-organotrophic bacterium, designated MCT, was isolated from a geothermally heated sediment of a marine hydrothermal system at Palaeochory Bay, Milos, Greece. Cells of strain MCT were rods of variable length (4–12 μm) and width (0.2–0.3 μm), occurring as single cells or forming large aggregates that were visible as flocs. Strain MCT grew optimally at pH 7.0 and 60 °C and with 3 % (w/v) NaCl. Strain MCT grew chemo-organoheterotrophically and fermented peptides and di- and polysaccharides in the presence of 0.1 g yeast extract l−1. The DNA G+C content of strain MCT was 43.3 mol%. Phylogenetic analysis of the 16S rRNA gene sequence placed strain MCT within the genus Caldithrix. However, strain MCT possessed certain phenotypic features that differentiated it from the type strain of the only species of the genus Caldithrix described to date. On the basis of phylogenetic and phenotypic characteristics, it is proposed that strain MCT represents a novel species, Caldithrix palaeochoryensis sp. nov. The type strain is MCT (=DSM 21940T =VKM B-2536T). In addition, an emended description of the genus Caldithrix is presented.