Idiomarina loihiensis sp nov., a halophilic γ-Proteobacterium from the L(o)over-bar-'ihi submarine volcano, Hawai'i

During an investigation of bacterial diversity at hydrothermal vents on the Lo'ihi Seamount, Hawai'i, a novel bacterium (designated L2-TRT) was cultivated, which shares 99-9% 16S rRNA gene sequence similarity over 1415 nt with an uncultured eubacterium from sediment at a depth of 11 000 m in the Mariana Trench. The nearest cultivated neighbour of L2-TRT, however, is Idiomarina abyssalis KMM 227(T), with which it shares 98.9% 16S rRNA sequence similarity. L2-TRT differed from I. abyssalis KMM 227(T) in several phenotypic respects, including growth at 46degreesC and in medium that contained 20% (w/v) NaCl. DNA-DNA hybridization data showed that L2-TRT did not belong to the species I. abyssalis (43.4% DNA-DNA reassociation). Cells of L2-TRT were Gram-negative rods, 0.35 mum wide and 0.7-1.0 mum long, which were occasionally up to 1.8 mum in length. Cells were motile by a single polar or subpolar flagellum. The major fatty acid in L2-TRT was iso-C-15:0 (32-6%). The DNA G+C content was 47.4 mol%. Phenotypic and genotypic analyses indicated that L2-TRT could be assigned to the genus Idiomarina but, based on significant phenotypic and genotypic differences, constituted a novel species within this genus, Idiomarina loihiensis sp. nov., of which L2-TRT (=ATCC BAA-735(T) =DSM 15497(T)) is the type strain.