Sulfitobacter geojensis sp. nov., Sulfitobacter noctilucae sp. nov., and Sulfitobacter noctilucicola sp. nov., isolated from coastal seawater

Abstract

Four Gram-stain-negative, aerobic, rod-shaped bacterial strains, MM-124, MM-126, NB-68 and NB-77, were isolated from the coastal seawater or a region with a bloom of sea sparkle around Geoje island in Korea. The sequence similarity values of the 16S rRNA gene between the isolates and Sulfitobacter mediterraneus DSM 12244T ranged from 97.7 to 98.2 %, and phylogenetic relationships suggested that they belong to a phylogenetic branch that includes the genera Sulfitobacter and Roseobacter . The isoprenoid quinone of all three novel strains was ubiquinone-10 and the major fatty acid was cis-vaccenic acid, as in other species of the genus Sulfitobacter . However, there were several differences in the morphological, physiological and biochemical characteristics among the four strains and the reference species of the genus Sulfitobacter . Moreover, the average nucleotide identity values between the three sequenced isolates and the reference strains were below 76.33, indicating that genomic variation exists between the isolates and reference strains. Chemotaxonomic characteristics together with phylogenetic affiliations and genomic distances illustrate that strains MM-124, NB-68 and NB-77 represent novel species of the genus Sulfitobacter , for which the names Sulfitobacter geojensis sp. nov. (type strain MM-124T = KCTC 32124T = JCM 18835T), Sulfitobacter noctilucae sp. nov. (type strain NB-68T = KCTC 32122T = JCM 18833T) and Sulfitobacter noctilucicola sp. nov. (type strain NB-77T = KCTC 32123T = JCM 18834T) are proposed.