Shewanella maritima sp. nov., a facultative anaerobic marine bacterium isolated from seawater, and emended description of Shewanella intestini.

A Gram-stain-negative, motile, facultative anaerobic rod-shaped marine bacterium, designated strain D4-2T, was isolated from a sample of seawater collected at Dong-do marina, Dokdo Island, in the East Sea of the Republic of Korea. Phylogenetic analysis based on the 16S rRNA gene sequences revealed that strain D4-2T was affiliated with members of genus Shewanella and closely related to Shewanella intestini XMDDZSB0408T (97.4%), followed by Shewanella gelidii RZB5-4T (96.7 %) and Shewanella inventionis KX27T (96.1 %). D4-2T has a single circular chromosome of 4.72 Mbp with a DNA G+C content of 44.5 mol%. Average nucleotide identity (ANI) and in silico DNA-DNA hybridization (DDH) values between strain D4-2T and the previously mentioned type strains of species of the genus Shewanella were in range of 69-83.8 % and 20.5-21.7 %, respectively. Growth was observed at 10-36 °C (optimum 29-32 °C), at pH 6-9 (optimum pH 7), and with 1-6% NaCl (optimum 2%). The predominant fatty acids (>10 %) of D4-2T were iso-C15:0 and summed feature 3 (C16:1ω7c and/or C16:1ω6c). The respiratory quinones were Q-7, Q-8, MK-7 and MMK-7. Phosphatidylethanolamine, phosphatidylglycerol, an unidentified aminophospholipid, an unidentified aminolipid and four unidentified lipids were detected in D4-2T. On the basis of phenotypic, chemotaxonomic and molecular properties, D4-2T represents a novel species of the genus Shewanella, for which the name Shewanella maritima sp. nov. is proposed with D4-2T as the type strain (=KCTC 72040T=JCM 33294T).