Phenylobacterium glaciei sp. nov., isolated from Vestrebroggerbreen, a valley glacier in Svalbard, Arctic

A Gram-stain-negative, rod-shaped bacterial strain designated as 20VBR1(T) was isolated from a valley glacier (Vestrebroggerbreen) snout ice sample from Ny-angstrom lesund, Svalbard, Arctic. The colonies were smooth, circular and light creamish on half-strength R2A agar and grew at 10-35 degrees C (optimum, 20 degrees C), at pH 6.5-8.0 ( optimum, 7.0) and with 0-2.5% (w/ v) NaCl (optimum, 0.5%). 16S rRNA gene sequence analysis revealed that strain 20VBR1(T) belonged to the genus Phenylobacterium and was most closely affiliated to Phenylobacterium aquaticum W2-3-4(T) ( 97.65 % similarity), Phenylobacterium haematophilum LMG 11050T (97.57 %) and Phenylobacterium koreense Slu-01(T) (96.91 %). 20VBR1(T) has a genome size of 4.24 Mb, comprising 4185 predicted genes with a DNA G+C content of 67.86 mol%. DNA-DNA hybridization experiments indicated that the DNA-DNA relatedness between strain 20VBR1(T) and P. aquaticum KACC 18306(T) was 41.95 +/- 4.36%, well below the threshold (<70 %) to delineate bacterial species. Genome relatedness indexes revealed that the average nucleotide identity and digital DNA-DNA hybridization values between 20VBR1(T) and its closest phylogenomic relative, P. aquaticum KACC 18306(T), were 78.97 and 22.10%, respectively. The predominant isoprenoid quinone was ubiquinone (Q-10) and the major polar lipids were phosphatidylglycerol, one unknown phospholipid, one unknown glycolipid and four unidentified polar lipids. The major fatty acids (>10 %) of strain 20VBR1(T) were summed feature 8 (comprising C-18:1 omega 7c and/or C-18:1 omega 6c), summed feature 3 (comprising C-16:1 omega 6c and/or C-16:1 omega 7c) and C-16:0. Based on the physiological, biochemical, chemotaxonomic, phylogenetic and phylogenomic analyses, isolate 20VBR1(T) is considered to represent a novel species of the genus Phenylobacterium, for which the name Phenylobacterium glaciei sp. nov. is proposed. The type strain is 20VBR1(T) (= JCM 33227 (T)=DSM 111428 (T)=MCC 4220 (T)).