Pseudorhodobacter antarcticus sp. nov., isolated from Antarctic intertidal sandy sediment, and emended description of the genus Pseudorhodobacter Uchino et al. 2002 emend. Jung et al. 2012.

A Gram-negative, aerobic, non-motile, pink-pigmented and rod-shaped strain, designated ZS3-33(T), was isolated from Antarctic intertidal sandy sediment. The strain grew optimally at 15 °C and with 1.0 % (w/v) NaCl. It reduced nitrate to nitrite and hydrolysed Tween 20. It could not produce bacteriochlorophyll a. The predominant cellular fatty acid was C18 : 1ω7c and the predominant respiratory quinone was Q-10. The major polar lipids were phosphatidylglycerol, phosphatidylcholine, two unidentified aminophospholipids and an unidentified aminolipid. Analyses of 16S rRNA gene sequences revealed that strain ZS3-33(T) belonged to the genus Pseudorhodobacter, showing 97.4 % similarity to the type strain of Pseudorhodobacter ferrugineus and 95.3 % similarity to the type strain of Pseudorhodobacter aquimaris. Levels of gyrB gene sequence similarity between strain ZS3-33(T) and the type strains of P. ferrugineus and P. aquimaris were 87.6 and 81.7 %, respectively. DNA-DNA relatedness between strain ZS3-33(T) and P. ferrugineus DSM 5888(T) was 56.6 %. The genomic DNA G+C content of strain ZS3-33(T) was 57.1 mol%. Based on data from this polyphasic study, strain ZS3-33(T) represents a novel species of the genus Pseudorhodobacter, for which the name Pseudorhodobacter antarcticus sp. nov. is proposed. The type strain is ZS3-33(T) ( = CGMCC 1.10836(T) = KCTC 23700(T)). An emended description of the genus Pseudorhodobacter Uchino et al. 2002 emend. Jung et al. 2012 is also proposed.