Marivita cryptomonadis gen. nov., sp nov and Marivita litorea sp nov., of the family Rhodobacteraceae, isolated from marine habitats

Two strictly aerobic, Gram-negative, rod-shaped bacteria containing photosynthesis-related genes, designated strains CL-SK44(T) and CL-JM1(T), were isolated from a culture of the marine phytoplankton Cryptomonas sp. and coastal seawater from Korea, respectively. Phylogenetic analysis of 16S rRNA gene sequences revealed that the two strains were related to members of the genera Thalassobius (95.3-96.7% similarity), Pelagibaca (95.3-96.0%) and Donghicola (95.6%) in the family Rhodobacteraceae. However, the two novel strains did not form a robust clade with any species of the Roseobacter clade, forming a distinct clade. The major polar lipids of the strains were phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, an unidentified aminolipid and an unidentified lipid, profiles that were distinguishable from those of the related genera examined. Although the level of 16S rRNA gene sequence similarity between strains CL-SK44(T) and CL-JM1(T) was very high (99.1%), DNA-DNA relatedness between the strains was 13%, suggesting that they represent genomically distinct species. In addition, the two strains could be differentiated based on the presence of a minor polar lipid, on the hydrolysis of gelatin and the utilization of carbon sources. Based on the data from the present study, strains CL-SK44(T) and CL-JM1(T) are considered to represent separate novel species of a new genus of the family Rhodobacteraceae, for which the names Marivita cryptomonadis gen. nov., sp. nov. (type species) and Marivita litorea sp. nov. are proposed. The type strains of Marivita cryptomonadis and Marivita litorea are CL-SK44(T) (=KCCM 90070(T)=JCM 15447(T)) and CL-JM1(T) (=KCCM 90071(T)=JCM 15446(T)), respectively.