Three novel actinobacteria, strains 39T, 40 and 41, were isolated from soil collected from Barrientos Island in the Antarctic. The taxonomic status of these strains was determined using a polyphasic approach. Comparison of 16S rRNA gene sequences revealed that strain 39T represented a novel lineage within the family
Dermacoccaceae
and was most closely related to members of the genera
Demetria
(96.9 % 16S rRNA gene sequence similarity),
Branchiibius
(95.7 %),
Dermacoccus
(94.4–95.3 %),
Calidifontibacter
(94.6 %),
Luteipulveratus
(94.3 %),
Yimella
(94.2 %) and
Kytococcus
(93.1 %). Cells were irregular cocci and short rods. The peptidoglycan type was A4α with an l-Lys–l-Ser–d-Asp interpeptide bridge. The cell-wall sugars were galactose and glucose. The major menaquinone was MK-8(H4). The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphoglycolipid, two glycolipids and one unknown phospholipid. The acyl type of the cell-wall polysaccharide was N-acetyl. The major cellular fatty acids were anteiso-C17 : 0 (41.97 %), anteiso-C17 : 1ω9c (32.16 %) and iso-C16 : 0 (7.68 %). The DNA G+C content of strain 39T was 68.4 mol%. On the basis of phylogenetic and phenotypic differences from other genera of the family
Dermacoccaceae
, a novel genus and species, Barrientosiimonas humi gen. nov., sp. nov., is proposed; the type strain of the type species is 39T ( = CGMCC 4.6864T = DSM 24617T).