Maribius salinus gen. nov., sp. nov., isolated from a solar saltern and Maribius pelagius sp. nov., cultured from the Sargasso Sea, belonging to the Roseobacter clade

1 School of Earth and Environmental Sciences and Research Institute of Oceanography, Seoul National University, Seoul 151-742, Republic of Korea 2 Division of Life and Marine Sciences, Inha University, Incheon 402-751, Republic of Korea 3 Department of Environmental Sciences, University of California, Riverside, CA 92521, USA 4 Department of Microbiology, Oregon State University, Corvallis, OR 97331, USA Correspondence Byung C. Cho bccho{at}snu.ac.kr Two strictly aerobic, Gram-negative bacteria, designated strains CL-SP27 T and B5-6 T , were isolated from the hypersaline water of a solar saltern in Korea and from the surface water of the Sargasso Sea, respectively. The two strains were rod-shaped, non-motile and grew on marine agar 2216 as beige colonies. Phylogenetic analyses of 16S rRNA gene sequences revealed a clear affiliation of the novel strains to the family Rhodobacteraceae . However, the novel strains were only distantly related to members of the Roseobacter clade, forming a distinct lineage. Although the 16S rRNA gene sequence similarity between strains CL-SP27 T and B5-6 T was very high (99.6 %), DNA–DNA relatedness between the strains was 48.4 %, suggesting that the strains be categorized as two genospecies. Additionally, the two novel strains could be differentiated by DNA G+C contents, fatty acid profiles, carbon source utilization patterns, antibiotic susceptibilities and biochemical characteristics. Based on taxonomic data obtained in this study, strains CL-SP27 T and B5-6 T represent separate species within a novel genus of the family Rhodobacteraceae , for which the names Maribius salinus gen. nov., sp. nov. (type species) and Maribius pelagius sp. nov. are proposed. The type strains of Maribius salinus and Maribius pelagius are CL-SP27 T (=KCCM 42113 T =JCM 13037 T ) and B5-6 T (=KCCM 42336 T =JCM 14009 T ), respectively. Abbreviations: PHB, poly -hydroxybutyrate The GenBank/EMBL/DDBJ accession numbers for the 16S rRNA gene sequences of strain CL-SP27 T and B5-6 T are AY906863 and DQ514326 , respectively. A table giving the major characteristics that differentiate strains CL-SP27 T and B5-6 T from other related members of the family Rhodobacteraceae is available as supplementary material in IJSEM Online. These authors contributed equally to this work. Present address: Marine Environmental Research Department, Korea Ocean Research and Development Institute (KORDI), Ansan 426-744, Republic of Korea.