Spongiibacter pelagi sp. nov., a marine gammaproteobacterium isolated from coastal seawater.

A novel gammaproteobacterium, designated as KMU-158, was isolated from seawater collected on the coastline of Dadaepo in the Republic of Korea, and characterized using a polyphasic taxonomic approach. Strain KMU-158 was Gram-staining-negative, pale beige-colored, strictly aerobic, rod-shaped, motile, and chemoorganoheterotrophic. The novel isolate was able to grow at 0-3% NaCl concentrations (w/v), pH 6.5-9.5, and 15-40 °C. The analysis based on 16S rRNA gene sequences indicated that strain KMU-158 belongs to the family Spongiibacteraceae and shared the highest similarity with Spongiibacter tropicus CL-CB221 (96.1%). The major cellular fatty acids were summed feature 3 (C ω7c and/or C ω6c) and C ω8c. The only respiratory quinone was identified as ubiquinone-8. The polar lipids of strain KMU-158 contained phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, and two unidentified lipids. The assembled draft genome size of strain KMU-158 was 3.29 Mbp with a DNA G + C content of 51.3%. The average nucleotide identity, digital DNA-DNA hybridization, and average amino acid identity values of KMU-158 and the representatives of the genus Spongiibacter were found to be 78.5-79.1%, 13.8-14.1%, and 66.6-66.8%, respectively. From the distinct phenotypic, phylogenetic, genomic, and chemotaxonomic properties, the strain KMU-158 is considered to represent a novel species of the genus Spongiibacter, for which the name Spongiibacter pelagi sp. nov. is proposed. The type strain of the species S. pelagi sp. nov. is KMU-158 (= KCCM 90448 = NBRC 114307).