Hirschia maritima sp nov., isolated from seawater

A Gram-negative, aerobic, orange-coloured bacterium, designated strain GSW-2(T), was isolated from seawater sampled at a beach and its taxonomic status was established by using a polyphasic approach. Vegetative cells produced a prostheca and reproduced by budding. Mature vegetative cells were spherical, oval- or rod-shaped (0.6-1.1 x 1.2-1.3 mu m) and both vegetative cells and buds produced one or more flagella. Cells grew well at 30 degrees C and at pH 8.1-9.1, and produced a non-diffusible pigment. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain GSW-2(T) was most closely related to the type strain of Hirschia baltica (97.5% similarity), a member of the family Hyphomonadaceae, class Alphaproteobacteria. Chemotaxonomic characteristics supported the assignment of strain GSW-2(T) to the genus Hirschia, including the dominant cellular fatty acids (summed feature 7 and C-16:0), isoprenoid quinone (mainly Q-10) and DNA G + C content (44.5 mol%). Levels of DNA-DNA relatedness between strain GSW-2(T) and Hirschia baltica DSM 5838(T) were 8.8-13.6%. On the basis of phenotypic features and DNA-DNA hybridization data, strain GSW-2(T) is considered to represent a novel species of the genus Hirschia, for which the name Hirschia maritima sp. nov. is proposed. The type strain is GSW-2(T) (= DSM 19733(T) = JCM 14974(T)).