Work

Flagellimonas ulvae sp. nov. and Flagellimonas rhodophyticola sp. nov., isolated from marine algae

Year: 2025

Type: article

Abstract: Two Gram-stain-negative, strictly aerobic, non-motile, rod-shaped bacteria, designated strains S174ᵀ and W118ᵀ, were isolated from the marine green alga Ulva prolifera and the marine red alga Schizymenia dubyi , respectively, collected in South Korea. Both strains exhibited catalase- and oxidase-positive activities and grew optimally at 25 °C, pH 8.0 and 2.0% (w/v) NaCl. The major fatty acids (>10%) in both strains were iso-C 15:1 G, iso-C 15:0 and iso-C 17:0 3-OH, with phosphatidylethanolamine as the major polar lipid and menaquinone-6 as the predominant respiratory quinone. The genomic DNA G+C contents, based on whole-genome sequences, were 39.1 mol% for both strains. Strains S174ᵀ and W118ᵀ shared 93.6% 16S rRNA gene sequence similarity, 72.7% average nucleotide identity (ANI) and 17.5% digital DNA–DNA hybridization (dDDH), supporting their classification as distinct species. Phylogenetic analyses based on 16S rRNA gene and genome sequences placed both strains in distinct lineages within the genus Flagellimonas . Strains S174ᵀ and W118ᵀ were most closely related to Flagellimonas meridianipacifica SW027ᵀ (97.2%) and Flagellimonas onchidii XY-359ᵀ (97.9%), respectively, and ANI and dDDH values with other type strains were below 84.6 and 28.2%, respectively, confirming their novelty. Based on phenotypic, chemotaxonomic and genomic features, strains S174ᵀ and W118ᵀ represent two novel species of the genus Flagellimonas , for which the names Flagellimonas ulvae sp. nov. (S174ᵀ=KACC 24029ᵀ=JCM 37803ᵀ) and Flagellimonas rhodophyticola sp. nov. (W118ᵀ=KACC 24030ᵀ=JCM 37802ᵀ) are proposed.

Source: INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY

DOI: 10.1099/ijsem.0.006996