Four Gram-stain-negative, strictly aerobic, catalase- and oxidase-positive bacterial strains, designated 2201CG5-10T, 2201CG14-23T, 2201CG1-2-11T, and 2304DJ70-9T were isolated from marine sponges collected in the Republic of Korea. Phylogenetic analyses based on 16S rRNA gene and whole-genome sequences revealed that these strains represent a distinct phyletic lineage within the genus Aquimarina. Based on the whole-genome sequence comparisons, the closest phylogenetic relatives of the four novel strains were Aquimarina latercula DSM 2041T, Aquimarina pacifica SW150T, and Aquimarina mytili PSC33T, which shared average nucleotide identity values below 81.3% and digital DNA-DNA hybridization values below 22.0% with the novel strains. The genomic DNA G + C contents of strains 2201CG5-10T, 2201CG14-23T, 2201CG1-2-11T, and 2304DJ70-9T were 32.5, 32.5, 33.5, and 34.0%, respectively. Menaquinone-6 was the sole isoprenoid quinone, and the predominant fatty acids were iso-C15:0, iso-C15:1 G, and iso-C17:0 3-OH. Phosphatidylethanolamine was the major polar lipid. Based on a polyphasic taxonomic approach, strains 2201CG5-10T (= KACC 23587T = JCM 36754T), 2201CG14-23T (= KACC 23588T = JCM 36755T), 2201CG1-2-11T (= KACC 23831T = JCM 33063T), and 2304DJ70-9T (= KACC 23830T = JCM 33063T = MCCC 1K09582T) represent four novel species of the genus Aquimarina, for which the names Aquimarina callyspongiae sp. nov., Aquimarina mycalae sp. nov., Aquimarina discodermiae sp. nov., and Aquimarina penaris sp. nov. are proposed.
Keywords: Bacteroidota; Marine sponge; Novel taxa; Phylogenetic analysis.
© 2025. The Author(s), under exclusive licence to Springer Nature Switzerland AG.