Psychrosphaera aestuarii sp. nov. and Psychrosphaera haliotis sp. nov., isolated from the marine environment, and emended description of the genus Psychrosphaera.

Two motile, rod-shaped and agarolytic bacterial strains, designated PSC101(T) and KDW4(T), were isolated from seawater and gut microflora of abalone, respectively, collected from the South Sea (Republic of Korea). Cells were Gram-stain-negative, aerobic, catalase- and oxidase-positive. Strains PSC101(T) and KDW4(T) showed high 16S rRNA gene sequence similarity to each other (98.6%). Psychrosphaera saromensis SA4-48(T) was the nearest neighbour of strains PSC101(T) and KDW4(T) with 96.6% and 97.0% 16S rRNA gene sequence similarity, respectively. DNA-DNA relatedness among strains PSC101(T), KDW4(T) and Psychrosphaera saromensis KCTC 23240(T) was less than 70%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the two isolates belonged to the genus Psychrosphaera and formed a distinct phyletic line from Psychrosphaera saromensis SA4-48(T). The common major cellular fatty acids of the two novel isolates were C(16 : 0), C(17 : 1)ω8c and summed feature 3 (C(16 : 1)ω6c/C(16 : 1)ω7c). Flexirubin-type pigments were absent. The main ubiquinone was UQ-8 and the DNA G+C content of strains PSC101(T) and KDW4(T) was 49.5 and 42.5 mol%, respectively. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and an unidentified amino lipid. On the basis of the polyphasic characterization of the two strains, it is suggested that the two isolates represent two novel species of the genus Psychrosphaera, for which the names Psychrosphaera aestuarii sp. nov. (type strain, PSC101(T) = KCTC 32274(T) = JCM 19496(T)) and Psychrosphaera haliotis sp. nov. (type strain, KDW4(T) = KCTC 22500(T) = JCM 16340(T)) are proposed. An emended description of the genus Psychrosphaera is also proposed.