A Gram-stain-negative, aerobic, yellow-coloured, motile by gliding, rod-shaped bacterial strain, designated R17H11T, was isolated from surface sediment collected from the Ross Sea, Antarctica. Growth optimally occurred at 25-30 °C, at pH 7.0-7.5 and in the presence of 3 % NaCl (w/v). Phylogenetic trees based on 16S rRNA gene sequences indicated that strain R17H11T clustered together with Gramella flava JLT2011T and fell within the genus Gramella. Strain R17H11T shared the highest 16S rRNA gene similarities (96.1 and 96.0 %) with the type strains of Gramella forsetii and G. flava, and 92.6-95.5 % similarities with those of other known Gramella species. Strain R17H11T contained menaquinone-6 as the only isoprenoid quinone. The major fatty acids (>5 %) were summed feature 3 (17.5 %, comprising C16 : 1ω7c and/or C16 : 1ω6c), iso-C15 : 0 (14.0 %), summed feature 9 (11.8 %, comprising 10-methyl C16 : 0 and/or iso-C17 : 1ω9c), iso-C17 : 0 3-OH (11.8 %), iso-C16 : 0 (7.4 %), C17 : 1ω6c (6.9 %) and anteiso-C15 : 0 (5.1 %). The major polar lipids were phosphatidylethanolamine, four unidentified lipids, an unidentified aminolipid, an unidentified aminophospholipid and an unidentified glycolipid. The DNA G+C content of strain R17H11T was 38.6 mol%. On the basis of the phylogenetic, physiological and chemotaxonomic characteristics, strain R17H11T represents a novel species in the genus Gramella, for which the name Gramellaantarctica sp. nov. is proposed. The type strain of the novel species is R17H11T (=GDMCC 1.1208T=KCTC 52925T).
Keywords: Antarctica; Flavobacteriaceae; Gramella; Ross Sea; marine sediment; polyphasic taxonomy.