Idiomarina loihiensis sp. nov., a halophilic γ-proteobacterium from the LŌ'ihi submarine volcano, Hawai'i

During an investigation of bacterial diversity at hydrothermal vents on the Lō'ihi Seamount, Hawai'i, a novel bacterium (designated L2-TR(T)) 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-TR(T), however, is Idiomarina abyssalis KMM 227(T), with which it shares 98.9 % 16S rRNA sequence similarity. L2-TR(T) differed from I. abyssalis KMM 227(T) in several phenotypic respects, including growth at 46 degrees C and in medium that contained 20 % (w/v) NaCl. DNA-DNA hybridization data showed that L2-TR(T) did not belong to the species I. abyssalis (43.4 % DNA-DNA reassociation). Cells of L2-TR(T) were Gram-negative rods, 0.35 microm wide and 0.7-1.0 microm long, which were occasionally up to 1.8 microm in length. Cells were motile by a single polar or subpolar flagellum. The major fatty acid in L2-TR(T) was iso-C(15 : 0) (32.6 %). The DNA G+C content was 47.4 mol%. Phenotypic and genotypic analyses indicated that L2-TR(T) 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-TR(T) (=ATCC BAA-735(T)=DSM 15497(T)) is the type strain.