Roseivivax pacificus sp. nov., isolated from deep-sea sediment.

A Gram-stain-negative, short-rod-shaped bacterium, designated 22DY03(T), was isolated from a sediment sample collected from the East Pacific Rise. The isolate required NaCl and grew best with 3-7 % (w/v) sea salts at temperature of between 30 and 35 °C at pH 7.0. It formed non-pigmented colonies and produced exopolysaccharide, but did not produce bacteriochlorophyll a. Strain 22DY03(T) was positive for hydrolysis of aesculin and Tween 20 and negative for hydrolysis of casein, DNA, gelatin, starch and Tween 40, 60 and 80. The major respiratory quinone was ubiquinone-10. The polar lipid profile consisted of a mixture of phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, diphosphatidylglycerol, two unidentified phospholipids and four unidentified polar lipids. The major fatty acids were C19 : 0 cyclo ω8c, C18 : 1ω7c and 11-methyl C18 : 1ω7c. The genomic DNA G+C content was 64.6 mol%. Phylogenetic analysis based on the 16S rRNA gene sequences indicated that strain 22DY03(T) should be assigned to the genus Roseivivax. The 16S rRNA gene sequence similarities between the isolate and the type strains of species of the genus Roseivivax were in the range of 94.1-95.8 %. On the basis of phenotypic and genotypic data, it is concluded that strain 22DY03(T) represents a novel species of the genus Roseivivax, for which the name Roseivivax pacificus sp. nov. (type strain 22DY03(T) = CGMCC 1.12410(T) = JCM 18866(T)) is proposed.