Choi Seo Hui, Baek Woonhee, Kim Jeong Min, Choi Byeong Jun, Bayburt Hülya, Lee Jae Kyeong, Lee Sung Chul, Jeon Che Ok
Department of Life Science, Chung-Ang University, 84, HeukSeok-Ro, Dongjak-Gu, Seoul, 06974, Republic of Korea.
Curr Microbiol. 2025 Sep 16;82(11):502. doi: 10.1007/s00284-025-04490-w.
Two Gram-stain-negative, catalase- and oxidase-positive, non-motile strains, S98ᵀ and JB4-11ᵀ, were isolated from marine red algae. Strain S98ᵀ was a strictly aerobic, ovoid to short rod-shaped bacterium that grew at 15-30 °C, pH 7.0-9.0, and 1.0-4.0% (w/v) NaCl. In contrast, strain JB4-11ᵀ was a facultatively anaerobic, rod-shaped bacterium that grew at 20-30 °C, pH 7.0-10.0, and 1.0-7.0% (w/v) NaCl. Both strains contained phosphatidylglycerol, phosphatidylcholine, two unidentified aminolipids, and an unidentified phospholipid as major polar lipids, with JB4-11ᵀ additionally possessing diphosphatidylglycerol. The predominant fatty acids were summed feature 8 (C ω7c and/or C ω6c) and C, and both strains contained ubiquinone-10 as the sole isoprenoid quinone. The genomic DNA G + C content was 60.0% for S98ᵀ and 60.6% for JB4-11ᵀ. Strains S98ᵀ and JB4-11ᵀ shared 97.3% 16S rRNA gene sequence similarity and formed distinct lineages from other Roseobacter and Sulfitobacter species, with ≤ 98.1% similarity, in 16S rRNA gene-based phylogenetic trees. Genome-based phylogenetic analyses revealed that strains S98ᵀ and JB4-11ᵀ clustered with Roseobacter cerasinus AI77ᵀ and Sulfitobacter aestuariivivens TSTF-M16ᵀ within the genera Roseobacter and Sulfitobacter, respectively. Average nucleotide identity and digital DNA-DNA hybridization values with other Roseobacter and Sulfitobacter species were below 75.9% and 19.7%, respectively. Based on phenotypic, chemotaxonomic, and genomic characteristics, strains S98ᵀ and JB4-11ᵀ represent novel species of Roseobacter and Sulfitobacter, for which the names Roseobacter algicola sp. nov. and Sulfitobacter rhodophyticola sp. nov. are proposed. The type strains are S98ᵀ (= KACC 23419ᵀ = JCM 36648ᵀ) and JB4-11ᵀ (= KACC 23867ᵀ = JCM 36646ᵀ), respectively.
从海洋红藻中分离出两株革兰氏染色阴性、过氧化氢酶和氧化酶阳性、无运动性的菌株，即S98ᵀ和JB4 - 11ᵀ。菌株S98ᵀ是严格需氧的，呈卵形至短杆状，在15 - 30 °C、pH 7.0 - 9.0和1.0 - 4.0%（w/v）NaCl条件下生长。相比之下，菌株JB4 - 11ᵀ是兼性厌氧的，杆状，在20 - 30 °C、pH 7.0 - 10.0和1.0 - 7.0%（w/v）NaCl条件下生长。两株菌株均含有磷脂酰甘油、磷脂酰胆碱、两种未鉴定的氨基脂质和一种未鉴定的磷脂作为主要极性脂质，其中JB4 - 11ᵀ还含有双磷脂酰甘油。主要脂肪酸为总和特征8（C ω7c和/或C ω6c）和C，两株菌株均以泛醌 - 10作为唯一的类异戊二烯醌。菌株S98ᵀ的基因组DNA G + C含量为60.0%，JB4 - 11ᵀ为60.6%。菌株S98ᵀ和JB4 - 11ᵀ的16S rRNA基因序列相似性为97.3%，在基于16S rRNA基因的系统发育树中与其他玫瑰杆菌属和硫杆菌属物种形成不同的分支，相似性≤98.1%。基于基因组的系统发育分析表明，菌株S98ᵀ和JB4 - 11ᵀ分别在玫瑰杆菌属和硫杆菌属内与角玫瑰杆菌AI77ᵀ和河口硫杆菌TSTF - M16ᵀ聚类。与其他玫瑰杆菌属和硫杆菌属物种的平均核苷酸同一性和数字DNA - DNA杂交值分别低于75.9%和19.7%。基于表型、化学分类和基因组特征，菌株S98ᵀ和JB4 - 11ᵀ代表玫瑰杆菌属和硫杆菌属的新物种，为此提出新名称嗜藻玫瑰杆菌（Roseobacter algicola sp. nov.）和红藻硫杆菌（Sulfitobacter rhodophyticola sp. nov.）。模式菌株分别为S98ᵀ（= KACC 23419ᵀ = JCM 36648ᵀ）和JB4 - 11ᵀ（= KACC 23867ᵀ = JCM 36646ᵀ）。
