Alkalimarinus alittae sp. nov., isolated from gut of marine sandworm ( Alitta virens) and emended description of the genus Alkalimarinus

Abstract

A novel, Gram-stain-negative, aerobic, motile, catalase- and oxidase-negative bacterial strain, designated A2M4T, was isolated from the gut contents of a marine sandworm Alitta virens, collected from the eastern coast of the Republic of Korea. Strain A2M4T formed translucent circular colonies and showed rod-shaped cells with peritrichous flagella. Optimal growth of strain A2M4T occurred at 25 °C, pH 7.0 and in the presence of 2 % (w/v) NaCl. Phylogenetic analysis based on the 16S rRNA gene sequences showed that strain A2M4T was closely related to Alkalimarinus sediminis FA028T, with the highest sequence similarity of 98.9 %. The complete genome sequence of strain A2M4T was 4.25 Mbp in size and the genomic G+C content, calculated from the genome sequence, was 43.2 mol%. A comparison between the genome sequence of strain A2M4T and that of its closest relative, A. sediminis FA028T, showed an average nucleotide identity value of 76.63 % and a digital DNA-DNA hybridization value of 22.2 %. Strain A2M4T contained Q-9 as the sole respiratory isoprenoid quinone and the major polar lipids were phosphatidylglycerol, diphosphatidylglycerol and phosphatidylethanolamine. The major cellular fatty acids of strain A2M4T were C14 : 0, C16 : 0 and summed feature 3 (comprising C16 : 1 ω7c and/or C16 : 1 ω6c). Based on its phenotypic, chemotaxonomic and genomic characteristics, strain A2M4T represents a novel species of the genus Alkalimarinus, for which the name Alkalimarinus alittae sp. nov. is proposed. The type is strain A2M4T (=KCTC 92030T=JCM 35924T). The description of the genus Alkalimarinus has also been emended.