Conexibacter woesei gen. nov., sp. nov., a novel representative of a deep evolutionary line of descent within the class Actinobacteria

A novel Gram-positive bacterial strain was isolated from forest soil. According to its 16S rRNA sequence, this strain is a deep-rooting member of the class Actinobacteria. The 16S rRNA sequence is most closely related (approximately 94% identity) to clones of uncultured bacteria detected in different terrestrial environments, while showing only a remote relationship (approximately 90% identity or less) to sequences of cultured species. Cells of the first cultured representative of this phylogenetic cluster are small, short rods that are motile by peritrichous flagella, catalase- and oxidase-positive and grow under aerobic conditions. In liquid culture, flagella from different cells can aggregate to form networks, clearly visible under the light microscope. The peptidoglycan contains meso-diaminopimelic acid and is directly cross-linked (type A1gamma). Mycolic acids are not present. The polar lipids are phosphatidylinositol and an unidentified phospholipid. Menaquinone MK-7(H4) was detected as the predominant isoprenoid quinone. Oleic, 14-methylpentadecanoic, hexadecanoic and omega6c-heptadecenoic acids are the predominant components of the cellular fatty acid profile. The DNA G + C content is 71 mol%. The distinct phylogenetic position and the unusual combination of chemotaxonomic characteristics justify the proposal of a new genus and species, Conexibacter woesei gen. nov., sp. nov., with the type strain ID131577T (=DSM 14684T =JCM 11494T).