Yoonia algicola sp. nov., Yoonia rhodophyticola sp. nov. and Yoonia phaeophyticola sp. nov., isolated from marine algae

Three Gram-stain-negative, strictly aerobic, non-motile, oxidase- and catalase-positive, short-rod-shaped bacteria, designated as strains G8-12^T, SS1-5^T and BS5-3^T, were isolated from marine algae in South Korea. Strain G8-12^T exhibited optimal growth at 20-25 °C, pH 8.0 and 2.0-2.5% (w/v) NaCl, while strains SS1-5^T and BS5-3^T grew optimally at 25 °C, pH 7.0 and 1.5% NaCl. All strains contained ubiquinone-10 as the sole respiratory quinone, with phosphatidylglycerol and phosphatidylcholine as major polar lipids, and C_{18 : 1} <i> ω</i>7<i>c</i> and C_{16 : 0} as major fatty acids (>5 %); C_{18 : 1} <i> ω</i>7<i>c</i> 11-methyl and C_{18 : 1} 2-OH were additionally identified as major fatty acids in strain SS1-5^T. The genomic DNA G+C contents were 57.0, 58.3 and 56.4% for strains G8-12^T, SS1-5^T and BS5-3^T, respectively. Strains G8-12^T, SS1-5^T and BS5-3^T exhibited less than 74.8% average nucleotide identity (ANI) and 19.7% digital DNA-DNA hybridization (dDDH) values with each other, indicating that they represent different species. Phylogenetic analyses based on both 16S rRNA gene and genome sequences revealed that strains G8-12^T, SS1-5^T and BS5-3^T form distinct phylogenetic lineages within the genus <i>Yoonia</i>. Relative to other closely related <i>Yoonia</i> species, these strains exhibited ANI and dDDH values below 83.5 and 26.9%, respectively, suggesting that they constitute novel species within the genus <i>Yoonia</i>. Based on their phenotypic, chemotaxonomic and phylogenetic characteristics, strains G8-12^T, SS1-5^T and BS5-3^T represent three novel species of the genus <i>Yoonia</i>, for which the names <i>Yoonia algicola</i> sp. nov. (G8-12^T=KACC 22753^T=JCM 35790^T), <i>Yoonia rhodophyticola</i> sp. nov. (SS1-5^T=KACC 22649^T=JCM 35753^T) and <i>Yoonia phaeophyticola</i> sp. nov. (BS5-3^T=KACC 22648^T=JCM 35751^T) are proposed, respectively.