Oh Young Joon, Kim Joon Yong, Kwon Min-Sung, Lee Sulhee, Choi Sang-Pil, Choi Hak-Jong
Technology Innovation Research Division, World Institute of Kimchi, Gwangju 61755, Republic of Korea.
J Microbiol. 2025 Jan;63(1):e.2501001. doi: 10.71150/jm.2501001. Epub 2025 Jan 24.
This study aimed to provide a taxonomic description of two bacterial strains, NKC19-3T and NKC19-16T, isolated from commercially produced kimchi obtained from various regions within the Republic of Korea. Both strains were rod-shaped, gram-stain-positive, facultatively anaerobic, and displayed positive reactions for oxidase and catalase. Additionally, these bacteria were motile, halophilic (salt-tolerant), and proliferated under alkaline conditions. Genetically, both strains showed 98.0% similarity in their 16S rRNA gene sequences and were most closely related to Virgibacillus natechei FarDT, with 96.5 and 96.8% sequence similarity, respectively. ANI values indicated that the two novel strains were distinct from V. natechei FarDT, as they were below the species demarcation threshold. The ANI value between strains NKC19-3ᵀ and NKC19-16ᵀ was 84.64-84.75%, and the values between these strains and other related strains did not exceed 80.0%, further supporting their classification as novel species. Phylogenetic analysis revealed that strains NKC19-3T and NKC19-16T formed a distinct branch within the genus Virgibacillus, clearly distinguishing them from other species in the same genus. Regarding genomic characteristics, the GC content was 38.9% for strain NKC19-3T and 39.5% for strain NKC19-16T. The genome of strain NKC19-3T had a size of approximately 4.1 Mb and contained 3,785 protein-coding genes (CDSs). Strain NKC19-16T had a slightly smaller genome, approximately 3.9 Mb in size and harbored 3,726 CDSs. The polar lipid profiles of strains NKC19-3ᵀ and NKC19-16ᵀ included diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), glycolipids (GL), and an unidentified lipid (L). The predominant fatty acids of both strains were anteiso-C15:0 and anteiso-C17:0. Considering the comprehensive analysis encompassing phenotypic, genomic, phylogenetic, and chemotaxonomic data, strains NKC19-3T and NKC19-16T are proposed to represent two novel species within the genus Virgibacillus. The suggested names for these species are Virgibacillus saliphilus sp. nov. (type strain NKC19-3T, also referred to as KACC 22326T and DSM 112707T) and Virgibacillus salidurans sp. nov. (type strain NKC19-16T, also referred to as KACC 22327T and DSM 112708T).
本研究旨在对从韩国不同地区商业化生产的泡菜中分离出的两株细菌NKC19 - 3T和NKC19 - 16T进行分类学描述。两株菌均为杆状，革兰氏染色阳性，兼性厌氧，氧化酶和过氧化氢酶反应呈阳性。此外，这些细菌具有运动性，嗜盐（耐盐），并在碱性条件下增殖。在基因方面，两株菌的16S rRNA基因序列相似度为98.0%，与纳特氏维尔吉芽孢杆菌FarDT关系最为密切，序列相似度分别为96.5%和96.8%。ANI值表明这两株新菌株与纳特氏维尔吉芽孢杆菌FarDT不同，因为它们低于物种划分阈值。菌株NKC19 - 3ᵀ和NKC19 - 16ᵀ之间的ANI值为84.64 - 84.75%，这些菌株与其他相关菌株之间的值不超过80.0%，进一步支持将它们分类为新物种。系统发育分析表明，菌株NKC19 - 3T和NKC19 - 16T在维尔吉芽孢杆菌属内形成一个独特的分支，明显区别于同一属中的其他物种。关于基因组特征，菌株NKC19 - 3T的GC含量为38.9%，菌株NKC19 - 16T的GC含量为39.5%。菌株NKC19 - 3T的基因组大小约为4.1 Mb，包含3785个蛋白质编码基因（CDS）。菌株NKC19 - 16T的基因组略小，大小约为3.9 Mb，含有3726个CDS。菌株NKC19 - 3ᵀ和NKC19 - 16ᵀ的极性脂质谱包括双磷脂酰甘油（DPG）、磷脂酰甘油（PG）、糖脂（GL）和一种未鉴定的脂质（L）。两株菌的主要脂肪酸为anteiso - C15:0和anteiso - C17:0。综合考虑表型、基因组、系统发育和化学分类学数据的全面分析，建议菌株NKC19 - 3T和NKC19 - 16T代表维尔吉芽孢杆菌属内两个新物种。这些物种的建议名称分别为嗜盐维尔吉芽孢杆菌（Virgibacillus saliphilus sp. nov.）（模式菌株NKC19 - 3T，也称为KACC 22326T和DSM 112707T）和耐碱维尔吉芽孢杆菌（Virgibacillus salidurans sp. nov.）（模式菌株NKC19 - 16T，也称为KACC 22327T和DSM 112708T）。
