Pseudorhodobacter psychrotolerans sp. nov., a psychrotolerant bacterium isolated from terrestrial soil, and emended description of the genus Pseudorhodobacter

Abstract

A Gram-staining-negative, falcultatively aerobic, cream-colored, ovoid-shaped, non-motile and psychrotolerant bacterial strain PAMC 27389T, was isolated from the terrestrial soil collected on the King George Island, Antarctica. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that strain PAMC 27389T belongs to the genus Pseudorhodobacter showing the high similarities with P. wandonensis (96.9 %), P. antarcticus (96.8 %), P. ferrugineus (96.5 %), and P. aquimaris (95.4 %). Average nucleotide identity values between strain PAMC 27389T and the type strains of P. wandonensis, P. antarcticus, P. ferrugineus, and P. aquimaris were 70.9, 70.8, 71.1, and 70.4 %, respectively and the genome-to-genome distance were 18.4-19.0 % on average, indicating PAMC 27389T is clearly distinguished from the most closely related Pseudorhodobacter species. The genomic DNA G+C content was 60.2 mol%. Strain PAMC 27389T grew at 0-37 ？C (optimally at 15-20 ？C), at pH 5.5-9.0 (optimally at 6.5-7.0) and in the presence of 0.5-30.0 % (w/v) (optimally at 0.5 %) of sea salt. The major fatty acids (≥ 5%) were Summed feature 8 (18:1 w9c, 86.50 %) and 18:1 w7c 11-methyl (5.4 %). The major polar lipids were one phosphatidylcholine, one phosphatidylglycerol, two unidentified phospholipids, two unidentified aminolipids, and two unidentified aminophospholipids. The major respiratory quinone was identified as Q-10. Based on the phenotypic, chemotaxonomic and genomic data presented, we propose the name Pseudorhodobacter psychrotolerans sp. nov. with the type strain PAMC 27389T (= KCTC 42640T = JCM 30764T).