Five Gram-negative, white-pigmented, spherical, chemoheterotrophic bacteria were isolated from seawater from Japan and the Republic of Palau by use of an in situ cultivation technique. Phylogenetic analyses based on 16S rRNA gene sequences indicated that the five novel isolates, 02PA-Ca-133T, YM14-201T, H-MN57T, H-MN48 and MN1-156, were closely affiliated to members of subdivision 4 within the phylum ‘Verrucomicrobia’. The novel isolates shared 96–100 % sequence similarity with each other and showed less than 90 % similarity with the cultivated strains of subdivision 4. DNA–DNA relatedness values between strains 02PA-Ca-133T, YM14-201T and H-MN57T were less than 70 %; the value commonly accepted as the threshold for the phylogenetic definition of a species. Antibiotic susceptibility tests and amino acid analysis of cell-wall hydrolysates indicated that the novel isolates did not contain muramic acid or diaminopimelic acid in their cell walls, suggesting that these strains lack peptidoglycan. The DNA G+C contents of the five strains were 51–57 mol%. The major menaquinone was MK-7 and C16 : 0, C16 : 1 ω7c and anteiso-C15 : 0 were the major fatty acids. On the basis of polyphasic taxonomic evidence, it is concluded that these strains should be classified as representing a new genus and three novel species in subdivision 4 of the phylum ‘Verrucomicrobia’, for which the names Pelagicoccus mobilis gen. nov., sp. nov. [type strain 02PA-Ca-133T (=MBIC08004T=IAM 15422T=KCTC 13126T)], Pelagicoccus albus sp. nov. [type strain YM14-201T (=MBIC08272T=IAM 15421T=KCTC 13124T)] and Pelagicoccus litoralis sp. nov. [type strain H-MN57T (=MBIC08273T=IAM 15423T=KCTC 13125T)] are proposed.
Three ionizing-radiation-resistant bacterial strains (designated KR-196, KR-198 and KR-200T) were isolated from a sample of arid soil collected from a coastal desert in Chile. The soil sample was irradiated before serial dilution plating was performed using one-tenth-strength plate count agar. Phylogenetic analysis of the 16S rRNA gene sequences showed these organisms to represent a novel species of the genus Deinococcus, having sequence similarities of 87.3–90.8 % with respect to recognized Deinococcus species. Strains KR-196, KR-198 and KR-200T were aerobic and showed optimum growth at 30 °C and pH 6.5–8.0. The major respiratory menaquinone was MK-8. The predominant fatty acids in these strains were 16 : 1ω7c, 16 : 0, 15 : 1ω6c, 17 : 0 and 18 : 0. The DNA G+C content of strain KR-200T was 63.9 mol%. Strains KR-196, KR-198 and KR-200T were found to be resistant to >10 kGy gamma radiation. On the basis of the phylogenetic, chemotaxonomic and phenotypic data, strain KR-200T represents a novel species of the genus Deinococcus, for which the name Deinococcus peraridilitoris sp. nov. is proposed. The type strain is KR-200T (=LMG 22246T=CIP 109416T).
A taxonomic study was carried out to clarify the status of a Gram-negative, heterotrophic mesophile that was isolated from the marine sponge Halichondria okadai. The strain, designated HOact23T, was a non-motile, rod-shaped (0.44–0.53×0.65–0.79 μm) bacterium. The strain produced squalene and a red–pink carotenoid pigment. The cell-wall peptidoglycan contained meso-diaminopimelic acid, glutamic acid and alanine. The G+C content of the genomic DNA was 52.4 mol%. The major fatty acids were iso-C14 : 0 (43.1 %), iso-C16 : 0 (20.6 %) and anteiso-C15 : 0 (18.1 %), and the major isoprenoid quinone was MK-9 (90.8 %). Based on 16S rRNA gene sequence data, the strain formed a distinct group within subdivision 1 in the phylum ‘Verrucomicrobia’. It showed a range of phenotypic properties that distinguished it from its closest relative, Rubritalea marina Pol012T (94.3 % 16S rRNA gene sequence similarity). On the basis of polyphasic taxonomic evidence, it was concluded that strain HOact23T should be classified within a novel species in the genus Rubritalea. The name proposed for the taxon is Rubritalea squalenifaciens sp. nov., with the type strain HOact23T (=MBIC08254T=DSM 18772T).