Thalassomonas
eurytherma sp. nov., a marine proteobacterium
Two Gram-staining-negative, aerobic, rod-shaped bacterial strains, designated Za6a-12T and Za6a-17, were isolated from seawater of the East China Sea. Cells of Za6a-12T and Za6a-17 were approximately 1.5–2.0 µm×0.5–0.7 µm and motile by a single polar flagellum. Strains grew optimally at pH 7.5-8.0, 28 °C, and in the presence of 2.5–3.0 % (w/v) NaCl. Chemotaxonomic analysis showed that the predominant respiratory quinone of strains Za6a-12T and Za6a-17 was ubiquinone-8 (>97 %), and the major fatty acids were C14 : 0, C16 : 1ω7c and/or iso-C15 : 0 2-OH, C16 : 0 and C17 : 1ω8c. Their DNA G+C contents were 42.7 mol% and 42.8 mol%, respectively. 16S rRNA gene sequence analysis revealed that the isolates belonged to the genus Thalassomonas and showed the highest sequence similarity to Thalassomonas loyana CBMAI 722T (95.9 %). Strains Za6a-12T and Za6a-17 could be differentiated from T. loyana CBMAI 722T according to their phenotypic and chemotaxonomic features, DNA G+C contents and fatty acid composition. On the basis of these features, we propose strains Za6a-12T and Za6a-17 to be representatives of a novel species of the genus Thalassomonas with the name Thalassomonas eurytherma sp. nov. suggested. Strain Za6a-12T ( = CGMCC 1.12115T = JCM 18482T) is the type strain of this novel species.