Tengunoibacter tsumagoiensis gen. nov., sp. nov., Dictyobacter kobayashii sp. nov., Dictyobacter alpinus sp. nov., and description of Dictyobacteraceae fam. nov. within the order Ktedonobacterales isolated from Tengu-no-mugimeshi, a soil-like granular mass of micro-organisms, and emended descriptions of the genera Ktedonobacter and Dictyobacter.

Three mesophilic, Gram-stain-positive, aerobic bacterial strains, designated Uno3, Uno11 and Uno16, were isolated from a soil-like granular micro-organism mass (termed Tengu-no-mugimeshi) collected from Tsumagoi, Gunma, Japan. They grow at 11-37 °C and pH 4.0-8.0, form branched mycelia, and have a G+C content between 49.4-50.3 mol%. The major menaquinone and fatty acid of Uno3 are MK-9 and iso-C16 : 0, respectively, whereas Uno11 and Uno16 share MK-9 (H2) and C16 : 1-2OH. The major cell-wall sugars are mannose (Uno3 and Uno11) and glucose (Uno16). Phylogenetic analysis based on 16S rRNA gene sequences indicated that these three strains belong to the order Ktedonobacterales and are most closely related to Dictyobacter aurantiacus S-27 (sequence similarity of 91.3, 96.4 and 95.5 %). Average nucleotide identity values were <79.9 % among Uno11, Uno16 and D. aurantiacus S-27, well below the 95-96 % species circumscription threshold. Based on phenotypic features and phylogenetic positions, we propose that Uno3 represents a novel genus and species, Tengunoibacter tsumagoiensis gen. nov., sp. nov. (type strain Uno3=NBRC 113152=LMG 30471=BCRC 81113) within the new family Dictyobacteraceae fam. nov. Strains Uno11 and Uno16 are also considered to represent novel species: Dictyobacterkobayashii sp. nov. (type strain Uno11=NBRC 113153=LMG 30472=BCRC 81114) and Dictyobacteralpinus sp. nov. (type strain Uno16=NBRC 113154=BCRC 81115). We also propose an emended description of the genus Dictyobacter, classifying it within family Dictyobacteraceae, and provide emended descriptions of the genera Dictyobacter and Ktedonobacter.