Thalassospira xianhensis sp. nov., a polycyclic aromatic hydrocarbon-degrading marine bacterium

A polycyclic aromatic hydrocarbon-degrading marine bacterium, designated strain P-4^T, was isolated from oil-polluted saline soil in Xianhe, Shangdong Province, China. Strain P-4^T was Gram-negative-staining with curved to spiral rod-shaped cells and grew optimally with 3-6% (w/v) NaCl and at 30 °C. The predominant fatty acids were C_{18 : 1}ω7c (35.0 %), C_{16 : 0} (25.0 %), C_{16 : 1}ω7c (17.9 %), C_{14 : 0} (6.2 %) and C_{17 : 0} cyclo (5.2 %). The major respiratory quinone was Q-9 and the genomic DNA G+C content was 61.2±1.0 mol%. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain P-4^T belonged to the genus Thalassospira of the class Alphaproteobacteria. DNA-DNA hybridization with Thalassospira xiamenensis DSM 17429^T showed relatedness of 36.0 %, and lower values were obtained with respect to other Thalassospira species. Based on physiological and biochemical tests and 16S rRNA gene sequence analysis as well as DNA-DNA relatedness, strain P-4^T should be placed in the genus Thalassospira within a novel species. The name Thalassospira xianhensis sp. nov. is proposed, with P-4^T (=CGMCC 1.6849^T =JCM 14850^T) as the type strain.