Algoriphagus algorifonticola sp. nov., a marine bacterium isolated from cold spring area of South China Sea

Abstract

A Gram-stain-negative, aerobic, non-motile, short-rod-shaped bacterium, designated strain hg1T, was isolated from marine sediment within the cold spring area of South China Sea and subjected to a polyphasic taxonomic investigation. Colonies were circular and 1.0–2.0 mm in diameter, coral in colour, convex and smooth after growth on marine agar at 28 °C for 3 days. Strain hg1T was found to grow at 4–40 °C (optimum, 35–37 °C), at pH 6.5–9.0 (optimum, pH 7.5) and with 0–8 % (w/v) NaCl (optimum, 1.5–2 %). Chemotaxonomic analysis showed the sole respiratory quinone was MK-7, and the principal fatty acids are iso-C15 : 0, summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), and iso-C16 : 0. The major polar lipids are phosphatidylethanolamine, an unidentified phospholipid and five unidentified glycolipids. The DNA G+C content of strain hg1T was 39.6 mol% based on the genome sequence. The comparison of 16S rRNA gene sequence similarities showed that hg1T was closely related to Algoriphagus ornithinivorans DSM 15282T (98.6 % sequence similarity), Algoriphagus zhangzhouensis MCCC 1F01099T (97.9 %) and Algoriphagus vanfongensis DSM 17529T (97.2 %); it exhibited 97.0 % or less sequence similarity to the type strains of other species of the genus Algoriphagus with validly published names. Phylogenetic trees reconstructed with the neighbour-joining, maximum-parsimony and maximum-likelihood methods based on 16S rRNA gene sequences showed that strain hg1T constituted a separate branch with A . ornithinivorans , A. zhangzhouensis , A. vanfongensis in a clade of the genus Algoriphagus . OrthoANI values between strain hg1T and A . ornithinivorans , A. zhangzhouensis and A. vanfongensis were 94.3, 74.1, 73.2 %, respectively, and in silico DNA–DNA hybridization values were 56.2, 18.5 and 18.3 %, respectively. Differential phenotypic properties, together with phylogenetic distinctiveness, demonstrated that strain hg1T is clearly distinct from recognized species of genus Algoriphagus . On the basis of these features, we propose that strain hg1T (=MCCC 1K03570T=KCTC 72111T) represents a novel species of the genus Algoriphagus with the name Algoriphagus algorifonticola sp. nov.