Rufibacter psychrotolerans sp. nov., a Cold-Tolerating Novel Species Isolated from Desert Soil

Strain SYSU D00308(T), a short-rod-shaped bacterium, was isolated from a sandy soil collected from the Gurbantunggut Desert, Xinjiang, PR China. Strain SYSU D00308(T) was Gram-stain-negative, aerobic, pink-pigmented, non-motile, catalase- and oxidase-positive. The strain grew at 4-37 degree celsius, pH 5.0-8.0 and 0-1.5% (w/v) NaCl. 16S rRNA gene sequencing analyses demonstrated that strain SYSU D00308(T) belonged to the genus Rufibacter and exhibited the highest sequence similarity (97.4%) to Rufibacter glacialis MDT1-10-3T. Summed features 3, 4, and iso-C-15:0 were the major fatty acids, and menaquinone 7 (MK-7) was the sole respiratory menaquinone. The polar lipid profiles comprised phosphatidylethanolamine, an unidentified glycolipid, an unidentified phospholipid, two unidentified aminophospholipids, and two unidentified lipids. The genome size and DNA G + C content of strain SYSU D00308(T) were 5,176,683 bp and 54.8%, respectively. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between SYSU D00308(T) and members of the genus Rufibacter were 77.7-81.8% and 20.4-23.4% respectively, which were less than the corresponding thresholds (ANI: 95-96%; dDDH: 70%) for prokaryotic species definition. According to the genotypic, phenotypic and phylogenetic characteristics, strain SYSU D00308(T) represents a novel species of the genus Rufibacter. We propose the name, Rufibacter psychrotolerans sp. nov., with SYSU D00308(T) (= CGMCC 1.18621T = KCTC 82275(T) = MCCC 1K04970(T)) as the type strain.