Antarcticirhabdus aurantiaca gen. nov., sp. nov., isolated from Antarctic gravel soil.

Strain R10 was isolated from a gravel soil sample obtained from Deception Island, Antarctica. The isolate was a Gram-stain-negative, strictly aerobic, motile, short-rod-shaped bacterium, and its colonies were orange yellow in colour. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain R10 belonged to the family and shared highest sequence similarity with LZB041 (96.3 % sequence similarity), R14M6 (96.0 %) and JCM 14755 (96.0 %). Phylogenetic analysis showed that strain R10 affiliated with members of the family and represented an independent lineage. Growth occurred at 10-37 °C (optimum, 28-32 °C), up to 1.0 % (w/v) NaCl (optimum, 0 %) and pH 5.5-9.0 (optimum, pH 7.0). The major respiratory quinone of strain R10 was Q-10. Its major fatty acids were C 7 and C. The polar lipid profile of strain R10 comprised diphosphatidylglycerol, phosphatidylmonomethylethanolamine, phosphatidylethanolamine, phosphatidylglycerol, two unknown phospholipids and two unknown aminophospholipids. The genome of strain R10 was 5.92 Mbp with a G+C content of 69.1 % based on total genome calculations. Average nucleotide identity (ANI) values between R10 and other related species of the family were found to be low (ANIm <87.0 %, ANIb <75.0 % and OrthoANIu <77.0 %). Furthermore, digital DNA-DNA hybridization (dDDH) and average amino acid identity (AAI) values between strain R10 and the closely related species ranged from 19.5-20.6% and from 60.6-64.0 %, respectively. Based on the results of our phylogenetic, phenotypic, genotypic and chemotaxonomic analyses, it is concluded that strain R10 represents a novel genus and species of the family , for which the name gen. nov., sp. nov. is proposed. The type strain is R10 (=KCTC 72466=CGMCC 1.17155).