Abstract
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-C 15 : 0 and C 16 : 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 126 T (=AIP 136.05 T =CIP 109408 T =CCUG 53819 T ) is 59.4 mol%.