Photobacterium aplysiae sp. nov., a lipolytic marine bacterium isolated from eggs of the sea hare Aplysia kurodai

Abstract

A bacterium, named GMD509T, showing lipolytic activity was isolated from the eggs of the sea hare Aplysia kurodai collected at Mogiyeo (depth, 12 m), an uninhabited small island in the South Sea of Korea. The strain is Gram-negative, motile, facultatively anaerobic, mesophilic and weakly halophilic. Optimal growth of strain GMD509T occurs in the presence of 3.0% (w/v) NaCl and at pH 8 and 25 °C. The whole-cell fatty acid profile of the isolate includes C16:1, C16:0 and C18:1 as major fatty acids and its DNA G+C content is 45 mol%. Phylogenetic analyses of 16S rRNA gene sequences place this bacterium in the γ-Proteobacteria, within the genus Photobacterium. The 16S rRNA gene sequence of strain GMD509T is most similar to those of Photobacterium frigidiphilum (97.8%), Photobacterium profundum (97.5%) and Photobacterium indicum (97.4%). DNA-DNA relatedness levels between the isolate and its closest known phylogenetic relatives, P. frigidiphilum and P. indicum, are 25.3 and 13.7%, respectively. Strain GMD509T therefore represents a novel species, for which the name Photobacterium aplysiae sp. nov. is proposed, with the type strain GMD509T (= KCTC 12383T = JCM 12948T). © 2005 IUMS.