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

Abstract

A marine bacterium, KOPRI 13342T, was isolated from a mature marine biofilms including various marine algae covered on a rock-bed of the East Sea, Korea. The strain produces an orange-coloured colony on marine agar 2216. The isolate showed relatively high 16S rRNA gene sequence similarities with members of the genera Maribacter (91.2-92.4% similarity), Zobellia (90.7-91.5%), and Muricauda (90.7-91.4%). Phylogenetic analysis based on nearly complete 16S rRNA gene sequence revealed that the isolate formed a phyletic lineage with members of the genus Muricauda. The cells were aerobic motile Gram-negative rods and produce non-diffusible carotenoid pigments. The optimal growth required the presence of 3 % (w/v) seasalt, pH 7.5-8.0 and 26-32 oC. The strain required Ca2+, K+, Mg2+ and CO32- in addition to the NaCl for growth. The dominant fatty acids are i-15:0, i-15:1, 15:0 and 16:1ω9. The major respiratory quinone is MK-6. The DNA G+C ratio is 35.8 mol%. On the basis of these polyphasic taxonomical evidences, strain KOPRI 13342T should be classified as a novel genus in the family Flavobacteriaceae and it is proposed as Costertonia aggregata gen. no., sp. nov. The type strain is KOPRI 13342T (=KCCM 42265T =JCM 13411T).