Butdee Waranya, Saimee Yuparat, Suriyachadkun Chanwit, Duangmal Kannika
Department of Microbiology, Faculty of Science, Kasetsart University, Chatuchak, Bangkok 10900, Thailand.
Present address: Division of Sustainable Energy and Environmental Engineering, Graduate School of Engineering, Osaka University, Suita, Japan.
Int J Syst Evol Microbiol. 2025 Jan;75(1). doi: 10.1099/ijsem.0.006608.
A novel strain DW16-2, isolated from duckweed (), was taxonomically studied in detail. The analysis based on its 16S rRNA gene sequence revealed that the strain was most closely related to Y8 (98.8%), followed by YIM 61452 (98.7%), DVS 5a1 (98.7%) and DSM 44104 (98.7%). The average nucleotide identity (ANI) based on blast and digital DNA-DNA hybridization (dDDH) relatedness values between strain DW16-2 and their closest type strains were below the threshold values for identifying a novel species. Morphological, physiological and chemotaxonomic features of strain DW16-2 were typical for the genus by forming extensively branched substrate mycelium and aerial mycelium that fragmented into rod-shaped spore, with a smooth surface. The whole-cell hydrolysates of strain DW16-2 contained -diaminopimelic acid as the diagnostic diamino acid, and the whole-cell sugars were arabinose, galactose, glucose and a trace amount of ribose. The polar lipids contained phosphatidylethanolamine, phosphatidylcholine, phosphatidylglycerol and unidentified phospholipids. The menaquinone (MK) was MK-8(H). The cellular fatty acids (>5 %) were -C, -C H, summed feature 3: C ω7c/C ω6c; C ω6c/C ω7c, C ω8c and -C. Characterization based on chemotaxonomic, phenotypic, genotypic and phylogenetic evidence demonstrated that strain DW16-2 represents a novel species of the genus , for which the name sp. nov. (type strain DW16-2 = TBRC 16418 = NBRC 115857) is proprosed. In addition, the comparison of the whole genome sequences suggested that and belong to the same species and is a subspecies of . Therefore, it is proposed that Prabahar . 2004 is reclassified as a later heterotypic synonym of (Evtushenko . 1989) Warwick . 1994, and Park . 2008 is proposed as a subspecies of (Evtushenko . 1989) Warwick . 1994.
从浮萍中分离出的一株新型菌株DW16-2进行了详细的分类学研究。基于其16S rRNA基因序列的分析表明，该菌株与Y8关系最为密切（98.8%），其次是YIM 61452（98.7%）、DVS 5a1（98.7%）和DSM 44104（98.7%）。基于blast和数字DNA-DNA杂交（dDDH）相关性值计算的菌株DW16-2与其最接近的模式菌株之间的平均核苷酸同一性（ANI）低于鉴定新物种的阈值。菌株DW16-2的形态、生理和化学分类特征对于该属而言具有典型性，其形成广泛分支的基内菌丝和气生菌丝，气生菌丝断裂成杆状孢子，表面光滑。菌株DW16-2的全细胞水解产物含有二氨基庚二酸作为特征性二氨基酸，全细胞糖类为阿拉伯糖、半乳糖、葡萄糖和微量核糖。极性脂质包含磷脂酰乙醇胺、磷脂酰胆碱、磷脂酰甘油和未鉴定的磷脂。甲基萘醌（MK）为MK-8（H）。细胞脂肪酸（>5%）为-C、-C H、总和特征3：C ω7c/C ω6c；C ω6c/C ω7c、C ω8c和-C。基于化学分类、表型、基因型和系统发育证据的特征表明，菌株DW16-2代表该属的一个新物种，为此提议命名为 sp. nov.（模式菌株DW16-2 = TBRC 16418 = NBRC 115857）。此外，全基因组序列的比较表明， 和 属于同一物种， 是 的一个亚种。因此，提议将Prabahar. 2004重新分类为（Evtushenko. 1989）Warwick. 1994的晚出异名，并且提议将Park. 2008作为（Evtushenko. 1989）Warwick. 1994的一个亚种。
