Abstract

A Gram-negative, aerobic, orange-coloured bacterium, designated strain GSW-2T, 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 (0.6-1.1x1.2-1.3 microm) 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-2T 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-2T to the genus Hirschia, including the dominant cellular fatty acids (summed feature 7 and C16:0), isoprenoid quinone (mainly Q-10) and DNA G+C content (44.5 mol%). Levels of DNA-DNA relatedness between strain GSW-2T and Hirschia baltica DSM 5838T were 8.8-13.6%. On the basis of phenotypic features and DNA-DNA hybridization data, strain GSW-2T 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-2T (=DSM 19733T=JCM 14974T).