Vulgatibacter incomptus gen. nov., sp. nov. and Labilithrix luteola gen. nov., sp. nov., two myxobacteria isolated from soil in Yakushima Island, and the description of Vulgatibacteraceae fam. nov., Labilitrichaceae fam. nov. and Anaeromyxobacteraceae fam

Two myxobacterial strains (designated B00001T and B00002T) were isolated from forest soil samples collected from Yakushima Island, Kagoshima, Japan. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strains B00001T and B00002T respectively formed independent branches within the suborders Cystobacterineae and Sorangiineae and were most closely related to Cystobacter armeniaca DSM 14710T (90.4 % similarity) and Byssovorax cruenta DSM 14553T (91.3 %). Neither strain showed typical features of myxobacteria such as bacteriolytic action or fruiting body formation, but both had high DNA G+C contents (66.3–68.3 mol%). Swarming motility was observed in strain B00002T only. Cells of both strains were vegetative, chemoheterotrophic, mesophilic, strictly aerobic, Gram-negative, motile rods, and both strains exhibited esterase lipase (C8), leucine arylamidase, naphthol-AS-BI-phosphohydrolase and β-galactosidase activities. Strain B00001T contained MK-7 as the predominant respiratory quinone and the major fatty acid was iso-C15 : 0. In contrast, strain B00002T contained MK-8 as the major cellular quinone and the major fatty acids were C16 : 1ω5c and iso-C17 : 0. Based on the phenotypic and genotypic data presented, strains B00001T and B00002T represent novel genera and species, for which we propose the names Vulgatibacter incomptus gen. nov., sp. nov. and Labilithrix luteola gen. nov., sp. nov., respectively. The type strains of Vulgatibacter incomptus and Labilithrix luteola are B00001T ( = NBRC 109945T = DSM 27710T) and B00002T ( = NBRC 109946T = DSM 27648T), respectively. The new genera are assigned to the new families Vulgatibacteraceae fam. nov. and Labilitrichaceae fam. nov., respectively. In addition, Anaeromyxobacteraceae fam. nov., is proposed to accommodate the genus Anaeromyxobacter , which is related to the genus Vulgatibacter.