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 degrees C. The predominant fatty acids were C(18 : 1)omega7c (35.0 %), C(16 : 0) (25.0 %), C(16 : 1)omega7c (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.