Congregibacter variabilis sp. nov. and Congregibacter brevis sp. nov. Within the OM60/NOR5 Clade, Isolated from Seawater, and Emended Description of the Genus Congregibacter

• Published in: The journal of microbiology Vol. 62; no. 9; pp. 739 - 748
• Main Authors: Tak, Hyeonsu, Park, Miri S., Cho, Hyerim, Lim, Yeonjung, Cho, Jang-Cheon
• Format: Journal Article
• Language: English
• Published: Seoul The Microbiological Society of Korea 01.09.2024; Springer Nature B.V; 한국미생물학회
• Subjects: Bacterial Typing Techniques; Base Composition; Biomedical and Life Sciences; Chemical analysis; coastal water; Coenzyme Q8; Deoxyribonucleic acid; DNA; DNA, Bacterial - genetics; Evolutionary Microbiology and Systematics; Fatty acids; Fatty Acids - analysis; Flagella; flagellum; Gene sequencing; Genome, Bacterial; Genomes; genomics; genus; Hybridization; isoprenoids; Korean Peninsula; Life Sciences; Lipids; Microbiological strains; Microbiology; New species; Nucleic Acid Hybridization; Nucleotide sequence; nucleotide sequences; Nucleotides; phenotype; Phosphatidylethanolamine; phosphatidylethanolamines; Phosphatidylglycerol; Phospholipids; Phospholipids - analysis; Phylogenetics; Phylogeny; Quinones; Republic of Korea; RNA, Ribosomal, 16S - genetics; rRNA 16S; Seawater; Seawater - microbiology; Sequence Analysis, DNA; sequence homology; species; Strains (organisms); Ubiquinone - analysis; Water analysis; Whole Genome Sequencing; 생물학; Republic of Korea; Korean Peninsula; New species; Polyphasic taxonomy; Seawater; Congregibacter variabilis; Congregibacter brevis
• ISSN: 1225-8873; 1976-3794; 1976-3794
• DOI: 10.1007/s12275-024-00158-5

Two Gram-stain-negative, aerobic, motile by means of flagella, short rod-shaped bacterial strains, designated IMCC43200 T and IMCC45268 T , were isolated from coastal seawater samples collected from the South Sea of Korea. Strains IMCC43200 T and IMCC45268 T shared 98.6% 16S rRNA gene sequence similarity and were closely related to Congregibacter litoralis KT71 T (98.8% and 98.7%, respectively). Complete whole-genome sequences of IMCC43200 T and IMCC45268 T were 3.93 and 3.86 Mb in size with DNA G + C contents of 54.8% and 54.2%, respectively. Average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between the two strains were 74.5% and 23.4%, respectively, revealing that they are independent species. The two strains showed ANI values of ≤ 75.8% and dDDH values of ≤ 23.0% to the type and only species of the genus Congregibacter ( C. litoralis ), indicating that each strain represents a novel species. Both strains contained summed feature 3 (comprising C 16:1 ω 6 c and/or C 16:1 ω 7 c ) and summed feature 8 (comprising C 18:1 ω 6 c and/or C 18:1 ω 7 c ) as major fatty acid constituents. The predominant isoprenoid quinone detected in both strains was ubiquinone-8 (Q-8). The major polar lipids of the two strains were phosphatidylethanolamine, phosphatidylglycerol, phospholipids, and aminolipids. Based on the phylogenetic, genomic, and phenotypic characterization, strains IMCC43200 T and IMCC45268 T were considered to represent two novel species within the genus Congregibacter , for which the names Congregibacter variabilis sp. nov. and Congregibacter brevis sp. nov. are proposed with IMCC43200 T (= KCTC 8133 T  = NBRC 116295 T  = CCTCC AB 2023139 T ) and IMCC45268 T (= KCTC 92921 T  = NBRC 116135 T ) as the type strains, respectively.