The genus Seonamhaeicola, meaning “southwest sea deweller” was proposed by Park et al. (2014). This genus includes several species, such as S. aphaedonensis (the type species) (Park et al., 2014), and others like S. algicola, S. sediminis, and S. marinus (Zhang et al., 2020). These species belonged to the family Flavobacteriaceae, one of the major phylogenetic lineages within the phylum Bacteroidota (Garrity and Holt, 2001; Oren and Garrity, 2021). Seonamhaeicola species are primarily isolated in marine environments, including tidal flat sediments, sea water, and marine algaal species (Park et al., 2014; Zhou et al., 2016; Kim and Chi, 2020; Zhang et al., 2020). Species like S. algicola are known for their ability to degrade complex polysaccharides, which is crucial for nutrient cycling in marine ecosystems (Zhou et al., 2016). By the association with marine algae, these bacteria may play a role in the health and growth of their host organisms (Fang et al., 2017). Diverse marine habitats of Seonamhaeicola suggest that they have evolved to adapt to different ecological niches such as varying salinity and organic carbon availability (Kim and Chi, 2020). In this study Seonamhaeicola sp. MEBiC01930 was isolated from the seaweed Eisenia bicyclis collected from the Dokdo Islands of Korea (37.2397 N, 131.8672 E).

Here we report complete genome sequence of Seonamhaeicola sp. MEBiC01930. The whole genome of the strain was sequenced using PacBio RSII at CJ BioScience Inc. The genome assembly for Seonamhaeicola sp. MEBiC01930 was conducted using the HGAP v. 3 method. Genome coverage was exceptionally high at 4,447.0x, indicating a very thorough sequencing process. The assembled sequences were functionally annotated using the NCBI Prokaryotic Genome Annotation Pipeline (PGAP) (Tatusova et al., 2016). The annotation method used by the process was “Best-placed reference protein set; GeneMarkS-2+, Revision 6.5”. The complete genome of Seonamhaeicola sp. MEBiC01930 was a single contig with 4,437.0x genome coverages, and the circular genome of 3,652,651 bp in length with a G-C content of 32.4%, and there were 3,111 predicted coding sequences (CDSs), 49 transfer RNAs (tRNA), 6 ribosomal RNA (rRNA), and 4 noncoding RNA (ncRNA) (Table 1).

Table 1

Genome assembly and annotation data of type strains from Seonamhaeicola sp. MEBiC1930

		Seonamhaeicola sp. MEBiC1930
Genome coverage		4437.0x
Total length		3,652,651 bp
%G + C ratio		32.4%
Annotated Features	Genes (total)	3,170
	CDSs (total)	3,111
	CDSs (with protein)	3,102
	Pseudo genes (CDS)	9
	Genes (RNA)	59
	rRNAs	2, 2, 2 (5S, 16S, 23S)
	complete rRNAs	2, 2, 2 (5S, 16S, 23S)
	tRNAs	49
	ncRNAs	4

When we used an automatic annotation of carbohydrate enzyme dbCAN3 (Zheng et al., 2023) on the genome of Seonamhaeicola sp. MEBiC01930, there were genes for alginate lyase activity; guluronate-specific alginate lyases, mannuronate-specific alginate lyases, and an oligo-alginate lyase. However, we could not find degradative enzymes for agar, carrageenan, and cellulose on the genome of MEBiC01930. According to the GenBank releases so far and strain MEBiC01930, genomes from Seonamhaeicola (n = 11) range in size from 3.47 to 5.06 Mb, with an average genome size of 3.99 ± 0.687( ) Mb. The reduced genomic size of Seonamhaeicola sp. MEBiC01930 in this study aligns with the roles that Flavobacteria play in the carbon cycles in marine environments (Park et al., 2014; Zhou et al., 2016). Hence, future studies are warranted on the variation in genomic sizes and the diverse niches among species of the genus Seonamhaeicola.

Nucleotide sequence accession numbers

Genome sequences for Seonamhaeicola sp. MEBiC01930 (= KCCM 42330 = JCM 14619) was deposited in GenBank/DDBJ/EMBL under the accession number of CP104270.1.

Bacteroidota 문(門) Flavobacteriaceae 과(科)에 속하는 Seonamhaeicola 속(屬)의 세균들은 주로 조간대 퇴적물, 해수 및 해양 조류와 같은 해양 환경에서 분리된다. 특히 S. algicola와 같은 종은 복잡한 다당류를 분해할 수 있어 해양 생태계에서 영양 순환에 중요한 역할을 한다. 여기서 우리는 한국 독도에서 수집한 해조류 Eisenia bicyclis에서 분리된 Seonamhaeicola sp. MEBiC01930의 완성 유전체 서열을 보고한다. 균주MEBiC193의 완성 유전체 서열은 3,652,651 bp로 구성되어 있으며 G-C 함량은 32.4%였다. 이 유전체 상에는 3,111개의 예측된 단백질 코딩 서열, 49개의 tRNA, 6개의 rRNA 및 4개의 ncRNA가 포함되어 있었다. 해양 환경에서 탄소 순환에 Flavobacteriaceae 과(科)에 속한 세균이 하는 역할을 고려하건데, Seonamhaeicola sp. MEBiC01930의 축소된 유전체 크기 및 유전체 변이를 통해 그 생태적 지위를 밝히는 연구가 필요하다.

This work was supported by Pukyong National University Research Fund (2024).

Hyun-Myung Oh is Editor of KJM. Prof. Oh was not involved in the review process of this article. Also, authors have no conflicts of interest to report.