Pseudoalteromonas arabiensis sp. nov., a marine polysaccharide-producing bacterium

A novel exopolysaccharide-producing bacterium, designated strain SE3T, was isolated from Pacific Ocean sediment. The strain was Gram-stain-negative, motile, strictly aerobic, oxidase-positive and catalase-positive, and required Na+ for growth. Its major isoprenoid quinone was ubiquinone-8 (Q-8), and its cellular fatty acid profile mainly consisted of C16 : 1ω7c, C16 : 0 and C18 : 1ω7c. The DNA G+C content was 46.9 mol%. 16S rRNA gene sequence analysis suggested that strain SE3T is a member of the genus Pseudoalteromonas . Strain SE3T exhibited close phylogenetic affinity to Pseudoalteromonas arabiensis JCM 17292T (99.0 % 16S rRNA gene sequence similarity), Pseudoalteromonas lipolytica LMEB 39T (98.39 %) and Pseudoalteromonas donghaensis HJ51T (97.65 %). The DNA–DNA reassociation values between strain SE3T and P. arabiensis JCM 17292T, P. lipolytica JCM 15903T and P. donghaensis LMG 24469T were 31, 26 and 44 %, respectively. Owing to the significant differences in phenotypic and chemotaxonomic characteristics, phylogenetic analysis based on 16S rRNA gene sequences and DNA–DNA relatedness data, the new isolate merits classification as a representative of novel species, for which the name Pseudoalteromonas shioyasakiensis is proposed. The type strain is SE3T ( = JCM 18891T = NCIMB 14852T).