
The genome of
The genus Flavivirga was first proposed by Yi et al. (2012), as a member of the family Flavobacteriaceae, class Flavobacteria, phylum Bacteroidetes, and encompasses four species with validly published names (LPSN, http://www.bacterio.net/). The members of the genus Flavivirga were isolated from marine environments such as seawater and seaweed (Lee et al., 2017). Members of the genus Flavivirga are Gram-strain-negative, aerobic, non-spore-forming, and rod-shaped with DNA G + C contents of 27~33 mol% and require sea salts for growth.
Alginate and cellulose are widely distributed in the cell wall of marine algae such as Ecklonia cava (Kim et al., 2016; Yagi et al., 2018). Many kinds of marine bacteria including Vibrio, Shewanella, Paenibacillus, and Bacillus were known to excrete alginate lyase and cellulase (Kim et al., 2016; Wang et al., 2017; Yagi et al., 2018; Zhu et al., 2018). These enzymes were known to decompose the dead algae in the marine environments and also concerned to produce bioactive oligosaccharides in industry (Kim et al., 2016; Wang et al., 2017).
Flavivirga eckloniae ECD14T was isolated from a seaweed Ecklonia cava collected from the South Sea, Republic of Korea and showed the degradation activity of seaweed polysaccharides alginate and cellulose (Lee et al., 2017). Thus, we determined the complete genome sequence of Flavivirga eckloniae ECD14T (= KCTC 52352T) and identified the presence of genes responsible for the degradation of seaweed polysaccharides. There were no whole genome sequence data on bacteria belonging to the genus Flavivirga.
The genomic DNA was extracted from the stationary phased cells using a Wizard genomic DNA isolation kit (Promega). The whole genome of ECD14T was determined using Pacific Biosciences (PacBio) RSII platform (Pacific Biosciences). Sequencing data were assembled with PacBio SMRT analysis using the HGAP2 protocol (Pacific Biosciences; Chin et al., 2013). The annotation of each CDS was made through National Center for Biotechnology Information prokaryotic genome Annotation Pipeline (Tatusova et al., 2016). Identification of clustered regularly interspaced short palindromic repeat (CRISPR) sequences was predicted by application CRISPRFinder program online (http://crispr.i2bc.paris-saclay.fr/Server/; Grissa et al., 2007).
The genome statistics are described in Table 1. The complete genome of strain ECD14T was composed of a single circular chromosome and did not contain any plasmid DNA. The 5,665,358 bp genome with a G + C content of 33.93% contained 4,595 coding regions (CDS), 44 pseudogenes, and 52 RNA genes (6 rRNA genes, 42 tRNA genes, and 4 non-coding RNA genes) based on NCBI’s Prokaryotic Genome Annotation Pipeline (PGAP) (Fig. 1). The pseudogenes make stop codon in the middle of nucleotides sequences that encode proteins. There were no contigs that had CRISPR which originates from, matched the corresponding parts of viral DNA and provided the cleaving site of Cas-proteins (Makarova et al., 2011). Five phage-related genes and transposable element genes could be annotated. The genome revealed the presence of two alginate lyases and five β-glucosidases, which involved in the degradation of alginate and cellulose, respectively. Also a monooxygenase gene associated with antibiotic biosynthesis and a gene related to the degradation of microcystin were found
The strain Flavivirga eckloniae ECD14T is available at KCTC 52352T and JCM 31797T.
Graphical circular map of
The genome sequence of Flavivirga eckloniae ECD14T has been deposited in NCBI GenBank under accession number CP025791.
This work was supported by Sunchon National University Research Fund in 2017.
대한민국 남해에서 채집한 해조류 감태(Ecklonia cava)로부터 분리한 Flavivirga eckloniae ECD14T 균주의 유전체서열을 분석하였다. 균주 ECD14T의 유전체는 G + C 비율이 33.9% 이며, 4,647개의 유전자와 4,595개의 단백질 코딩 유전자, 44개의 위유전자, 52개의 RNA 유전자를 포함한 단일 원형 염색체로 구성되었으며 그 크기는 2,371,912 bp였다. 파아지와 트랜스포존 유전자가 존재하며, CISPR array 관련 유전자 및 서열은 발견되지 않았다. 균주 ECD14T는 해조 다당의 분해에 관여하는 alginate lyase와 β-glucosidase 유전자를 가지고 있었다.
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