Arthrobacter antarcticus sp. nov., isolated from an Antarctic marine sediment.

A bacterial strain, SPC26(T), was isolated from a sediment sample of the Southern Ocean off Antarctica. The strain was Gram-staining- and catalase-positive and contained lysine and alanine in the cell-wall peptidoglycan. The major cellular fatty acids were anteiso-C₁₅:₀ (54.92 %), iso-C₁₅:₀ (11.47 %), anteiso-C₁₇:₀ (6.48 %) and anteiso-C₁₅:₁ (6.38 %) and the major menaquinones were MK-8, MK-9 and MK-10. The major polar lipids were phosphatidylethanolamine and diphosphatidylglycerol. The G+C content was 68 ± 0.5 mol%. Based on 16S rRNA gene sequence similarities, the nearest phylogenetic neighbours of strain SPC26(T) were identified as Arthrobacter gangotriensis Lz1y(T) (98.8 %), A. sulfureus DSM 20167(T) (98.6 %), A. psychrophenolicus DSM 15454(T) (97.9 %) and A. kerguelensis KGN15(T) (97.5). With these strains, strain SPC26(T) exhibited DNA-DNA relatedness values of 36, 21, 12 and 10 %, respectively. Therefore, on the basis of 16S rRNA gene sequence comparisons, phylogenetic analysis, phenotypic characteristics and DNA-DNA relatedness, it is proposed that strain SPC26(T) represents a novel species of Arthrobacter, for which the name Arthrobacter antarcticus sp. nov. is proposed, with strain SPC26(T) (=LMG 24542(T) =NCCB 100228(T)) as the type strain.