Devosia psychrophila sp. nov. and Devosia glacialis sp. nov., from alpine glacier cryoconite, and an emended description of the genus Devosia

Abstract

Two psychrophilic strains, Cr7-05T and Cr4-44T, isolated from alpine glacier cryoconite, were characterized by using a polyphasic approach. Both strains were psychrophilic, showing good growth over a temperature range of 1–20 °C. The chemotaxonomic characteristics of these isolates included the presence of C18 : 1ω7c and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) as the major cellular fatty acids, Q-10 as the predominant ubiquinone and diphosphatidylglycerol, phosphatidylglycerol and unknown glycolipids as major polar lipids. The DNA G+C contents of strains Cr7-05T and Cr4-44T were 61.4 and 63.6 mol%, respectively. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the two isolates belong to the genus Devosia. The 16S rRNA gene sequence similarity between the two strains was 98.6 %, but DNA–DNA hybridization indicated 54 % relatedness. Strains Cr7-05T and Cr4-44T exhibited 16S rRNA gene sequence similarity of 94.7–97.2 and 94.9–96.9 %, respectively, to the type strains of recognized Devosia species. On the basis of phenotypic characteristics, phylogenetic analysis and DNA–DNA relatedness data, strains Cr7-05T and Cr4-44T represent two novel species within the genus Devosia, for which the names Devosia psychrophila sp. nov. (type strain Cr7-05T  = DSM 22950T  = CGMCC 1.10210T  = CIP 110130T) and Devosia glacialis sp. nov. (type strain Cr4-44T  = CGMCC 1.10691T  = LMG 26051T) are proposed. An emended description of the genus Devosia is also provided.