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

Strain SYSU D00308, a short-rod-shaped bacterium, was isolated from a sandy soil collected from the Gurbantunggut Desert, Xinjiang, PR China. Strain SYSU D00308 was Gram-stain-negative, aerobic, pink-pigmented, non-motile, catalase- and oxidase-positive. The strain grew at 4-37 ℃, pH 5.0-8.0 and 0-1.5% (w/v) NaCl. 16S rRNA gene sequencing analyses demonstrated that strain SYSU D00308 belonged to the genus Rufibacter and exhibited the highest sequence similarity (97.4%) to Rufibacter glacialis MDT1-10-3. Summed features 3, 4, and iso-C 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 were 5,176,683 bp and 54.8%, respectively. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between SYSU D00308 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 represents a novel species of the genus Rufibacter. We propose the name, Rufibacter psychrotolerans sp. nov., with SYSU D00308 (= CGMCC 1.18621 = KCTC 82275 = MCCC 1K04970) as the type strain.