Spirosoma arcticum sp. nov., isolated from high Arctic glacial till

Abstract

A novel orange-pigmented strain, designated R2-35T, was isolated from a glacier till near Ny-Alesund, Svalbard Archipelago, Norway. The cells were aerobic, Gram-negative, rod-shaped and sometimes filamentous. Growth occurred at 4–28 °C (optimum, 20 °C), at pH 7.0–9.0 (optimum, pH 8.0) and with 0–1 % NaCl. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain R2-35T belonged to the genus Spirosoma with sequence similarity to related species ranging from 91.65 to 95.19 %. Strain R2-35T contained C16 : 0 (10.7 %), C18 : 0 (9.2 %), C16 : 1ω5c (16.5 %) and summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c) (24.6 %) as the major cellular fatty acids, MK-7 as the major respiratory quinone, and phosphatidylethanolamine as the main polar lipid. The DNA G+C content of strain R2-35T was 54.9 mol%. On the basis of phylogenetic, physiological and chemotaxonomic data, strain R2-35T is considered to represent a novel species of the genus Spirosoma , for which the name Spirosoma arcticum sp. nov., is proposed, The type strain is R2-35T ( = CCTCC AB 2012849T = LMG 28141T).