Costertonia aggregata gen. nov., sp nov., a mesophilic marine bacterium of the family Flavobacteriaceae, isolated from a mature biofilm

A marine bacterium, strain KOPIRI 13342(T), was isolated from a mature marine biofilm, including various marine algae, covering a rock-bed of the East Sea, Korea (also known as the Sea of Japan). Colonies of the isolate were orange-coloured on marine agar 2216. The isolate showed relatively high 16S rRNA gene sequence similarities to members of the genera Maribacter (91(.)2-92(.)4% similarity), Zobeffia (90(.)7-91(.)5%) and Muricauda (90(.)7-91(.)4%). Phylogenetic analysis based on the nearly complete 16S rRNA gene sequence revealed that the isolate formed a phyletic lineage with members of the genus Muricauda. Cells were aerobic, motile, Gram-negative rods and they produced non-diffusible carotenoid pigments. Optimal growth was observed at pH 7(.)5-8(.)0 and 26-32 degrees C and required the presence of 3% (w/v) sea salt. The strain required Ca2+ and K+ ions in addition to NaCl for growth. The dominant fatty acids were i-15:0, i-15:1 omega 10, 15:0 and 16:1 omega 9. The major respiratory quinone was MK-6. The DNA G+C content was 35(.)8 mol%. On the basis of this polyphasic taxonomic evidence, strain KOPRI 13342 T should be classified as a representative of a novel species in a new genus in the family Flavobacteriaceae; the name Costertonia aggregata gen. nov., sp. nov. is proposed. The type strain of Costertonia aggregata is KOPRI 13342(T) (=KCCM 42265(T) = JCM 13411(T)).