sp. nov., a novel bacterium with great antioxidant capacity isolated from the north slope of Mount Everest.

A bacterial strain, designated S8-55, was isolated from moraine samples collected from the north slope of Mount Everest at an altitude of 5 500 m above sea level. The purpose of this study was to describe a novel species and its characteristics, through genome sequencing and analysis of the relationship between the members of the genus , and explore the antioxidant capacity of strain S8-55. The polyphasic study confirmed the affiliation of strain S8-55 with the genus . Strain S8-55 was aerobic, Gram-negative and oxidase- and catalase positive. Cells were orange-pigmented, ellipsoid and had no spore formation, no flagella and no motility. Strain S8-55 grow at 10-37 °C, pH 7-11 and without NaCl. Ubiquinone 10 was its predominant respiratory menaquinone. The polar lipids of strain S8-55 were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, an unidentified phospholipid, an unidentified aminolipid and three unidentified lipids. Its major fatty acids were summed feature 8 (C 7 and/or C 6). The G+C content was 64.3 mol%. The phylogenetic analysis based on the 16S rRNA sequence showed that strain S8-55 was closely related to E6 (97.9 %), 011410 (97.9 %) and THG-T2.8 (97.8 %). The average nucleotide identity values among strain S8-55 and CCTCC AB 2015056, KCTC 42845 and CCTCC AB 2016181 were 84.1, 84.5 and 76.3 %, respectively. The genome of strain S8-55 contained antioxidant genes such as , , , and . Based on its morphological, physiological and chemical taxonomic characteristics, strain S8-55 (=JCM 35 227=GDMCC 1.3026) should be classified as a novel species of the genus with the proposed name sp. nov.