Azoarcus pumilus sp. nov., isolated from seawater in Sanya, China

A novel Gram-stain-negative, motile, rod-shaped (0.4-0.5 x 1.0-2.0 mu m) strain with one polar flagellum, designated SY39(T), was isolated from seawater in Sanya, China. Strain SY39(T) was able to grow at 15-40 degrees C (optimum, 35-37 degrees C), pH 6.5-8.5 (pH 8.0) and 0.5-6.0 % (w/v) NaCl (3.5 %). Chemotaxonomic analysis showed that the isoprenoid quinones were Q-8 (88.6 %) and Q-7 (11.4 %). The dominant fatty acids were C-16(:0) and summed feature 3 (C-16(:1)omega 7c/C-16(:1)omega 6c). The polar lipids of strain SY39(T) consisted of diphosphatidyglycerol, phosphatidylglycerol, phosphatidylethanolamine, one unknown phosphoglycolipid, one unknown glycolipid and two unknown aminophosphoglycolipids. The DNA G+C content of the genomic DNA was 66.5 mol%. The phylogenetic analysis of 16S rRNA gene sequences showed that strain SY39(T) belongs to the genus Azoarcus with similarity ranging from 92.3 to 95.2 %. Based on the phenotypic, chemotaxonomic and phylogenetic features, strain SY39(T) is concluded to represent a novel species of the genus Azoarcus, for which the name Azoarcus pumilus sp. nov. is proposed. The type strain is SY39(T) (=KCTC 62157(T) = MCCC 1K03430(T)).