A Gram-stain-negative, rod-shaped, red-pigmented bacterium (MDT1-10-3 T ) was isolated from Midui glacier in Tibet, China. Cells were aerobic and psychrotolerant (growth occurred at 4-25 8C). Phylogenetic analysis based on 16S rRNA gene sequences indicated that it was a member of the genus Rufibacter, with Rufibacter immobilis MCC P1 T (96.7 % similarity) as its closest phylogenetic relative. MK-7 was the predominant respiratory menaquinone. The major cellular fatty acids were summed feature 4 (iso-C 17 : 1 I and/or anteiso-C 17 : 1 B), summed feature 3 (C 16 : 1 v6c and/or C 16 : 1 v7c), C 17 : 1 v6c, iso-C 16 : 0 , iso-C 15 : 0 and C 16 : 1 v5c. The predominant polar lipids were phosphatidylethanolamine, two unidentified aminophospholipids, one glycolipid and four unidentified lipids. The G+C content of the genomic DNA was 49 mol%. On the basis of the phenotypic characteristics and phylogenetic analysis, strain MDT1-10-3 T represents a novel species of the genus Rufibacter, for which the name Rufibacter glacialis sp. nov. is proposed. The type strain is MDT1-10-3 T (5CGMCC 1.9789 T 5NBRC 109705 T ).The genus Rufibacter was originally created by Abaydulla et al. (2012), and comprises aerobic Gram-stain-negative, catalase-and oxidase-positive, non-spore-forming bacteria. Menaquinone-7 (MK-7) is the major respiratory menaquinone and phosphatidylethanolamine is the predominant polar lipid of the genus Rufibacter. The genus comprises, at the time of writing, three recognized species (Abaydulla et al., 2012;Polkade et al., 2015; Zhang et al., 2015). During a study of bacterial diversity on glaciers in China, a strain producing red colonies (MDT1-10-3 T ) was isolated from soil collected from Midui glacier, Tibet, China. In this study, we describe the morphological, biochemical and phylogenetic characteristics of strain MDT1-10-3 T , employing the closely related type strains Rufibacter immobilis CCTCC AB 2013351 T and Rufibacter tibetensis CCTCC AB 208084 T as reference strains in parallel tests for phenotypic and fatty acid analysis. The reference strains were obtained from the Chinese Centre for type Cultures Collections.Strain MDT1-10-3 T was isolated using R2A agar at 14 8C and stored at 280 8C in 20 % (v/v) glycerol. Colony morphology was observed on R2A agar after incubation at 20 8C for 5 days. Growths at different temperatures (4, 14, 18, 20, 22, 25, 30 8C), different NaCl concentrations [0-4 % (w/v), at intervals of 1 %] and different pH (4.0-12.0, at intervals of 1.0 pH unit) were examined in R2A broth. The R2A broth used to test pH range was adjusted by using the biological buffers Na 2 HPO 4 / NaH 2 PO 4 (for pH 4-8) and Na 2 CO 3 /NaHCO 3 (for pH 9-12), and filter-sterilized. Cell morphology and dimensions were observed using a JEM