Sphingomonas glacialis sp. nov., a psychrophilic bacterium isolated from alpine glacier cryoconite

Abstract

A non-motile, rod-shaped, yellow bacterium, designated C16y(T), was isolated from alpine glacier cryoconite. Cells behaved Gram-positively, were aerobic and psychrophilic (good growth at 1-25 °C). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain C16y(T) was related to the genus Sphingomonas and had highest 16S rRNA gene sequence similarity with Sphingomonas oligophenolica JCM 12082(T) (97.6 %) and Sphingomonas echinoides DSM 1805(T) (97.2 %). DNA-DNA hybridization demonstrated that strain C16y(T) could not be considered as a member of either Sphingomonas oligophenolica or Sphingomonas echinoides. Strain C16y(T) contained Q-10 as the predominant ubiquinone and C₁₈:₁ and C₁₆:₀ were the dominant fatty acids. The polar lipid profile contained phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, sphingoglycolipid, five unidentified glycolipids, two unidentified aminophospholipids and two unidentified lipids. The major polyamines were the triamines sym-homospermidine and spermidine. The G+C content was 67.9 mol%. Combined data from phenotypic, phylogenetic and DNA-DNA relatedness studies demonstrated that strain C16y(T) is a representative of a novel species of the genus Sphingomonas, for which we propose the name Sphingomonas glacialis sp. nov. The type strain is C16y(T) (=DSM 22294(T) =CGMCC 1.8957(T) =CIP 110131(T) [corrected]).