A Gram-stain-negative, aerobic, yellow-pigmented, non-flagellated, non-gliding, rod-like, oxidase- and catalase-positive bacterium, designated A2-1T, was isolated from soil on Ardley Island, South Shetland Islands, Antarctica. Strain A2-1T grew at 4-22 °C (optimum, 10 °C), at pH 6.0-8.0 (optimum, pH 6.5) and with 0-1.5 % NaCl (optimum, 0.5 %), but could not produce flexirubin-type pigments. 16S rRNA gene sequence analysis showed that the isolates belonged to the genus Flavobacterium. Strain A2-1T had the highest 16S rRNA gene sequence similarity to Flavobacterium cucumis, F. ahnfeltiae and F. cheniae with 95.7, 95.6 and 95.4 %, respectively. The strain A2-1T consisted of a clade with F. cucumis and F. cheniae and simultaneously formed a distinct phyletic lineage in the neighbour-joining phylogenetic tree. Polar lipids of the strain included phosphatidylethanolamine (PE), four unidentified aminolipids and one unidentified lipid. The strain A2-1T contained anteiso-C15 : 0 (20.2 %), iso-C15 : 0 (16.2 %) and C15 : 1 G (11.0 %) as the main fatty acids and the only respiratory quinone was menaquinone MK-6. The genomic DNA G+C content was 34.0 mol%. The polyphasic taxonomic study revealed that the strain A2-1T belongs to a novel species within the genus Flavobacterium and the name Flavobacterium ardleyense sp. nov. is proposed. The type strain is A2-1T (=CCTCC AB 2017157T=KCTC 52644T).
Keywords: Antarctic soil; Polyphasic taxonomy; The genus Flavobacterium; sp. nov.