Arthrobacter cheniae and Arthrobacter frigidicola sp. nov., isolated from a glacier

Two Gram-stain-positive, aerobic, rod-shaped, pink and light pink colony-forming bacteria, designated as Hz2(T) and MDT2-14(T), respectively, were isolated from glacier cryoconite samples. Comparisons based on 16S rRNA gene sequences showed that strains Hz2(T) and MDT2-14(T) take Arthrobacter bussei KR32(T) and Arthrobacter zhaoguopingii J391(T) as their closest neighbours, respectively. The average nucleotide identity values between the two novel strains and their closest relatives were 83.56 and 93.06%, respectively. The two strains contain MK-9(H-2) as their predominant menaquinone. The polar lipids of both strains were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol and an unidentified glycolipid. The major fatty acids of strain Hz2(T) were anteiso-C-15:0, summed feature 3 (comprising C-16:1 omega 7c and/or C-16:1 omega 6c) and iso-C-15:0, while the major fatty acids of strain MDT2-14(T) were anteiso-C-15:0 and anteiso-C-17:0. Based on these data, we propose two novel species, Arthrobacter cheniae sp. nov. (Hz2(T) = CGMCC 1.9262(T)=NBRC 113086(T)) and Arthrobacter frigidicola sp. nov. (MDT2-14(T)=CGMCC 1.9882(T)=NBRC 113089(T)).