Description of an anaerobic actinobacterium, gen. nov., sp. nov., a new member of the novel family fam. nov., and reclassification of the genera and .

Two rod-shaped, obligate anaerobic, Gram-stain-positive bacteria isolated from the pig faeces were designated YH-ols2216 and YH-ols2217. Analysis of 16S rRNA gene sequences revealed that these isolates were most related to the members of the family , within the order , and KCTC 25474 with 92.0 and 92.5% similarities, respectively. The 16S rRNA gene sequence similarity within isolates was 99.9 %; and those between isolates YH-ols2216 and YH-ols2217, and DSM 20586, the type species of the type genus within the family , were 88.5 and 88.7 %, respectively. Those between isolates and PW2, the type species of the type genus within the family , were 88.7 and 89.1 %, respectively. The multi-locus sequence tree revealed that the isolates, alongside the genera and , formed a distinct cluster between the families and . The average nucleotide identities and digital DNA-DNA hybridization values for the isolates and their most closely related strains ranged from 67.7 to 76.2 % and from 18.4 to 23.3 %, respectively. The main cellular fatty acids of the isolates were C DMA, C 9, C 12OH, C, and C. The cell wall contained the peptidoglycan -diaminopimelic acid. Lactate was the main end-product of the isolates. The major polar lipids of isolate YH-ols2217 were aminophospholipid, aminolipids, and lipids. Menaquinones were not identified in the cells of the isolates. The DNA G+C contents of isolates YH-ols2216 and YH-ols2217 were 67.5 and 67.6 mol%, respectively. Considering these chemotaxonomic, phenotypic, and phylogenetic properties, fam. nov. is proposed within the order . YH-ols2216 (=KCTC 25708=NBRC 116429) and YH-ols2217 (=KCTC 25709=NBRC 116430) represent a novel taxon within this new family and the name gen. nov., sp. nov. is proposed. In addition, the genera and are transferred to the family fam. nov.