Pseudoroseicyclus aestuarii gen. nov., sp. nov., isolated from a tidal flat.

A Gram-stain-negative, non-motile, aerobic and coccoid, ovoid or rod-shaped bacterial strain, designated DB-4T, was isolated from a tidal flat of the Yellow Sea, South Korea. Strain DB-4T grew optimally at 30 °C, at pH 7.0-8.0 and in the presence of approximately 1.0-2.0 % (w/v) NaCl. Phylogenetic trees based on 16S rRNA gene sequences revealed that strain DB-4T clustered with the type strain of Roseicyclus mahoneyensis, showing sequence similarity of 94.8 %. It exhibited sequence similarity values of 95.6-96.1 % to the type strains of Loktanella soesokkakensis, Loktanella hongkongensis, Loktanella variabilis, Loktanella aestuariicola and Loktanella cinnabarina. Strain DB-4T contained Q-10 as the predominant ubiquinone and C18:1ω7c and cyclo C19:0ω8c as the major fatty acids. The major polar lipids of strain DB-4T were phosphatidylcholine, phosphatidylglycerol and one unidentified aminolipid. The fatty acid and polar lipid profiles of strain DB-4T were distinguished from those of the type strains of R. mahoneyensis and some phylogenetically related Loktanella species. The DNA G+C content of strain DB-4T was 69.2 mol%. On the basis of the phylogenetic, chemotaxonomic and other phenotypic properties, strain DB-4T is considered to represent a novel species of a new genus within the family Rhodobacteraceae, for which the name Pseudoroseicyclus aestuarii gen. nov., sp. nov. is proposed. The type strain ofPseudoroseicyclus aestuarii is DB-4T (=KCTC 52038T=CECT 9025T).