Roseomonas fluminis sp. nov. isolated from sediment of a shallow stream.

An aerobic, Gram-negative, motile by means of a single polar flagellum, and ovoid-shaped bacterium, designated D3, was isolated from shallow stream sediments in Sinan-gun, South Korea. Growth occurred at 15-40 °C (optimum 35 °C), at pH 7.0-8.0 (optimum pH 7.0), and at an optimum NaCl concentration of 0.5 % (w/v). The major cellular fatty acids (>7 % of the total) were C16 : 0, C18 : 0 2-OH, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c). The predominant quinone was ubiquinone-10, and the G+C content of the genomic DNA of strain D3 was 73.1 mol%. The major polyamine was spermidine. The major polar lipids of the isolate were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine and phosphatidylglycerol. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain D3 clustered with Roseomonas aquatica TR53 within the genus Roseomonas. The 16S rRNA gene sequence of strain D3 showed the highest sequence similarity to R. aquatica TR53 (95.9 %), followed by Roseomonas rosea 173-96 (95.7 %) and Roseomonas aerilata 5420S-30 (95.0 %). Based on the phenotypic, phylogenetic and chemotaxonomic characterization, strain D3 represents a novel species of the genus Roseomonas, for which the name Roseomonas fluminis sp. nov. is proposed. The type strain is D3 (=KACC 19269=JCM 31968).