Arthrobacter antioxidans sp. nov., a blue pigment-producing species isolated from Mount Everest.

Bacteria in the genus Arthrobacter have been found in extreme environments, e.g. glaciers, brine and mural paintings. Here, we report the discovery of a novel pink-coloured bacterium, strain QL17 ^T , capable of producing an extracellular water-soluble blue pigment. The bacterium was isolated from the soil of the East Rongbuk Glacier of Mt. Everest, China. 16S rRNA gene sequence analysis showed that strain QL17 ^T was most closely related to the species Arthrobacter bussei KR32 ^T . However, compared to A.bussei KR32 ^T and the next closest relatives, the new species demonstrates considerable phylogenetic distance at the whole-genome level, with an average nucleotide identity of <85 % and inferred DNA-DNA hybridization of <30 %. Polyphasic taxonomy results support our conclusion that strain QL17 ^T represents a novel species of the genus Arthrobacter . Strain QL17 ^T had the highest tolerance to hydrogen peroxide at 400 mM. Whole-genome sequencing of strain QL17 ^T revealed the presence of numerous cold-adaptation, antioxidation and UV resistance-associated genes, which are related to adaptation to the extreme environment of Mt. Everest. Results of this study characterized a novel psychrotolerant Arthrobacter species, for which the name Arthrobacter antioxidans sp. nov. is proposed. The type strain is QL17 ^T (GDMCC 1.2948 ^T =JCM 35246 ^T ).