sp. nov., sp. nov., and sp. nov., isolated from dried beach seaweeds.

Three actinobacterial strains, KSW2-21, KSW2-29 and KSW4-17, were isolated from dried seaweeds collected around Gwakji Beach in Jeju, Republic of Korea. Their taxonomic positions were determined based on genomic, physiological and morphological characteristics. The isolates were Gram-positive, aerobic, non-motile, rod-shaped bacteria characterized by the following chemotaxonomic features: ornithine as the cell wall diamino acid, the -glycolyl type of murein, MK-11 as the predominant menaquinone, polar lipids including diphosphatidylglycerol, phosphatidylglycerol, two unidentified glycolipids and four unidentified phospholipids, with anteiso-C, iso-C and anteiso-C as the the major fatty acids. The 16S rRNA gene phylogeny showed that the novel strains formed three distinct sublines within the genus . Strain KSW4-17 formed a tight cluster with the type strain of , while strains KSW2-21 and KSW2-29 occupied distinct positions between the type strains of and . Strains KSW4-17 and KSW2-29 showed 99.9 % rRNA gene sequence similarity to CGMCC 1.12512, while strain KSW2-21 revealed 99.4 % 16S rRNA gene sequence similarity to the type strains of and . The genome sizes and genomic G+C contents of the three isolates ranged from 3.44 to 3.74 Mbp and from 70.3 to 70.8 mol%, respectively. The phylogenomic tree based on 92 core gene sequences exhibited similar topologies to the 16S rRNA gene phylogeny. The comparison of overall genomic relatedness indices, such as average nucleotide indentity and digital DNA-DNA hybridization, supported that the isolates represent three new species of the genus . Based on the results obtained here, sp. nov. (type strain, KSW2-21=KACC 23322=DSM 116381), sp. nov. (type strain KSW2-29=KACC 22350=NBRC 115221) and sp. nov. (type strain, KSW4-17=KACC 23323=DSM 116383) are proposed.