Six clinical isolates of a hitherto unknown, strictly anaerobic, Gram-negative rod showing fastidious growth were subjected to a polyphasic taxonomic study, including phenotypic, genomic and phylogenetic feature analyses. 16S rRNA gene sequenced-based phylogeny revealed that the novel strains represent a homogeneous group distant from any recognized species in the candidate phylum ‘Synergistetes’. The novel isolates were most closely related to species of the genus Dethiosulfovibrio, with 88.2–88.7 % 16S rRNA gene sequence similarity. Large-scale chromosome structure and DNA G+C content also differentiated the novel strains from members of the genus Dethiosulfovibrio. The novel strains were asaccharolytic. Major metabolic end products in trypticase/glucose/yeast extract broth were acetic, lactic, succinic and isovaleric acids and the major cellular fatty acids iso-C15 : 0 and C16 : 0. Based on the data presented here, a new genus, Jonquetella gen. nov., is proposed with one novel species, Jonquetella anthropi sp. nov. J. anthropi is the first characterized species of the candidate phylum ‘Synergistetes’ that includes human isolates. The G+C content of the DNA of the type strain of J. anthropi ADV 126T (=AIP 136.05T=CIP 109408T=CCUG 53819T) is 59.4 mol%.
An obligately aerobic, spherical, non-motile, pale-yellow pigmented bacterium was isolated from a piece of leaf of seagrass, Enhalus acoroides (L.f.) Royle, grown in Okinawa, Japan and was subjected to a polyphasic taxonomic study. Phylogenetic analyses based on 16S rRNA gene sequences revealed that the novel isolate N5FB36-5T shared approximately 96–98 % sequence similarity with the species of the genus Pelagicoccus of the family Puniceicoccaceae within the phylum ‘Verrucomicrobia’. The DNA–DNA relatedness values of strain N5FB36-5T with Pelagicoccus mobilis 02PA-Ca-133T and Pelagicoccus albus YM14-201T were below 70 %, which is accepted as the phylogenetic definition of a novel species. β-Lactam antibiotic susceptibility test and amino acid analysis of the cell wall hydrolysates indicated the absence of muramic acid and diaminopimelic acid in the cell walls, which suggested that this strain lacks an ordinary Gram-negative type of peptidoglycan in the cell wall. The DNA G+C content of strain N5FB36-5T was 51.6 mol%; MK-7 was the major menaquinone; and the presence of C16 : 0, C16 : 1 ω7c and anteiso-C15 : 0 as the major cellular fatty acids supported the identification of the novel isolate as a member of the genus Pelagicoccus. On the basis of polyphasic taxonomic data, it was concluded that this strain should be classified as a novel species of the genus Pelagicoccus, for which the name Pelagicoccus croceus sp. nov. is proposed. The type strain is N5FB36-5T (=MBIC08282T=KCTC 12903T).