Polymorphobacter glacialis sp. nov., isolated from ice core.

A Gram-stain-negative, non-spore-forming, rod-shaped bacterium, B555-2, was isolated from an ice core drilled from Muztagh Glacier on the Tibetan Plateau, China. According to phylogenetic analysis with 16S rRNA gene sequences, the novel strain was most closely related to Polymorphobacter fuscus D40P and Polymorphobacter multimanifer 262-7 with 98.4 and 96.9 % similarity, respectively. It grew optimally at pH 7 and 15 °C with 0.6 % NaCl (m/v). Carotenoid was detected from the cells. Major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, sphingoglycolipid, phophatidylmonomethy lethanolamine, phophatidylcholine. The major fatty acids were summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH) (42.8 %), summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) (28.8 %), C14 : 0 2-OH (10.1 %) and C16 : 0 (8.2 %). The predominant ubiquinone was Q-10. The DNA G+C content was 62.1 mol%. In DNA-DNA hybridization tests, strain B555-2 shared 21.9 and 18.6 % DNA-DNA relatedness with P. fuscus D40P and P.multimanifer 262-7, respectively. Accordingly, strain B555-2 represents a novel species in the genus Polymorphobacter, for which the name Polymorphobacter glacialis sp. nov. is proposed. The type strain is B555-2 (=CGMCC 1.15519=KCTC 52396).