Yin Chenyu, Pan Suwan, Zhai Yuanwei, Wang Lili, Yao Jiaqi, Zhang Ya, Li Rongpeng, Jiang Jihong, Cao Chengliang
The Key Laboratory of Biotechnology for Medicinal Plant of Jiangsu Province, College of Life Science, Jiangsu Normal University, Xuzhou, 221116, PR China.
The Key Laboratory of Microbial Resources of Xuzhou City, College of Life Science, Jiangsu Normal University, Xuzhou, 221116, PR China.
Int J Syst Evol Microbiol. 2025 Jul;75(7). doi: 10.1099/ijsem.0.006853.
Strain KLBMP 9127, isolated from dolomite weathering crusts, was subjected to comprehensive taxonomic characterization using a polyphasic taxonomic approach. Strain KLBMP 9127 is an aerobic, Gram-stain-positive bacterium with coccoid to short rod-shaped cells that forms stromal mycelia and spherical sporangia. This Gram-positive strain exhibits chemotaxonomic features characteristic of the genus. The genus is characterized by the presence of meso-diaminopimelic acid and madurose in whole-organism hydrolysates, and menaquinones MK-9(H) and MK-9(H) are the predominant respiratory quinones. The predominant fatty acid (>10%) of strain KLBMP 9127 was identified as C (17.6%) and C 10-methyl (22.3%). Phylogenetic analysis based on 16S rRNA gene sequences revealed that KLBMP 9127 forms a distinct lineage within the clade, showing 97.2% sequence similarity with its closest relative, DSM 43180. Genomic comparisons of KLBMP 9127 demonstrated digital DNA-DNA hybridization (dDDH) and average nt identity (ANI) values of 24.1% and 81%, respectively, both falling below the recommended thresholds for species demarcation (dDDH≥70%; ANI≥95-96%). Comprehensive phenotypic profiling (cell wall composition, menaquinone profiles and fatty acid methyl esters) and genomic evidence conclusively distinguish KLBMP 9127 from related taxa. Based on these cumulative findings, strain KLBMP 9127 was proposed as the type strain of a novel species, sp. nov., with the designation KLBMP 9127 (=CGMCC 4.7739=NBRC 115834). Genomic analysis identified 23 biosynthetic gene clusters encoding specialized metabolites, including polyketide synthases, nonribosomal peptide synthetases and enediyne-type antitumour compound pathways. In antitumour proliferation experiments, within the tested concentration range of 5-200 µg ml, the inhibition rate gradually increased from 13.7% (at 5 µg ml) to 99.1% (at 200 µg ml). This extensive biosynthetic potential highlights the strain's significant capacity for producing novel antibiotics and antineoplastic agents, underscoring the biotechnological importance of this genus in natural product discovery.
从白云石风化壳中分离出的菌株KLBMP 9127，采用多相分类方法进行了全面的分类学表征。菌株KLBMP 9127是一种需氧的革兰氏阳性细菌，细胞呈球状至短杆状，形成基质菌丝体和球形孢子囊。这种革兰氏阳性菌株表现出该属特有的化学分类学特征。该属的特征是在全细胞水解物中存在内消旋二氨基庚二酸和马杜拉糖，并且甲基萘醌MK-9(H)和MK-9(H)是主要的呼吸醌。菌株KLBMP 9127的主要脂肪酸（>10%）被鉴定为C（17.6%）和C 10-甲基（22.3%）。基于16S rRNA基因序列的系统发育分析表明，KLBMP 9127在该进化枝内形成了一个独特的谱系，与其最接近的亲缘种DSM 43180的序列相似性为97.2%。KLBMP 9127的基因组比较显示，数字DNA-DNA杂交（dDDH）值和平均核苷酸同一性（ANI）值分别为24.1%和81%，均低于物种划分的推荐阈值（dDDH≥70%；ANI≥95-96%）。全面的表型分析（细胞壁组成、甲基萘醌谱和脂肪酸甲酯）和基因组证据明确地将KLBMP 9127与相关分类群区分开来。基于这些累积发现，菌株KLBMP 9127被提议作为一个新物种的模式菌株，即新种，命名为KLBMP 9127（=CGMCC 4.7739=NBRC 115834）。基因组分析鉴定出23个编码特殊代谢产物的生物合成基因簇，包括聚酮合酶、非核糖体肽合成酶和烯二炔类抗肿瘤化合物途径。在抗肿瘤增殖实验中，在5-200μg/ml的测试浓度范围内，抑制率从13.7%（5μg/ml时）逐渐增加到99.1%（200μg/ml时）。这种广泛的生物合成潜力突出了该菌株产生新型抗生素和抗肿瘤药物的显著能力，强调了该属在天然产物发现中的生物技术重要性。
