Choi Yujin, Ganzorig Munkhtsatsral, Lee Kyoung
Department of Bio Health Science, Changwon National University, Changwon 51140, Gyeongnam, Republic of Korea.
Microorganisms. 2025 Jan 6;13(1):94. doi: 10.3390/microorganisms13010094.
The genus comprises important soil bacteria that are often associated with the crop rhizospheres, but its physiological traits remain poorly understood. This study characterizes sp. TT6, isolated from human skin, with a focus on its metabolic and environmental adaptations. Genome sequencing and phylogenomic analyses revealed that the strain TT6 is most closely related to M1, with average nucleotide identity and digital DNA-DNA hybridization values of 94.14% (±0.5%) and 64.7%, respectively. Comparative genomic analysis showed that the strains TT6, M1 and 8-14-6 share the Calvin cycle, and possess photosynthetic genes associated with the purple bacteria-type photosystem II. The strains TT6 and M1 exhibited growth in a nitrogen-free medium under microaerobic conditions, which were generated in test tubes containing 0.1% soft agar. Under these conditions, with nitrate as a nitrogen source, M1 formed gases, indicating denitrification. Strain TT6 also contains gene clusters involved in trehalose and carotenoid biosynthesis, along with salt-dependent colony morphology changes, highlighting its adaptive versatility. Genomic analyses further identified pathways related to hydrogenase and sulfur oxidation. Phenotypic and chemotaxonomic traits of strain TT6 were also compared with closely related type strains, confirming its genotypic and phenotypic distinctiveness. The new species, sp. nov., is proposed, with TT6 (=KCTC 82306 = JCM 34945) as the type strain. This study underscores the agricultural and ecological significance of the genus .
该属包含重要的土壤细菌，这些细菌通常与作物根际相关，但对其生理特性的了解仍然很少。本研究对从人类皮肤分离出的TT6菌株进行了表征，重点关注其代谢和环境适应性。基因组测序和系统发育基因组分析表明，菌株TT6与M1关系最为密切，平均核苷酸同一性和数字DNA-DNA杂交值分别为94.14%（±0.5%）和64.7%。比较基因组分析表明，菌株TT6、M1和8-14-6共享卡尔文循环，并拥有与紫色细菌型光系统II相关的光合基因。菌株TT6和M1在含有0.1%软琼脂的试管中产生的微需氧条件下，能在无氮培养基中生长。在这些条件下，以硝酸盐作为氮源，M1产生气体，表明发生了反硝化作用。菌株TT6还含有参与海藻糖和类胡萝卜素生物合成的基因簇，以及盐依赖性菌落形态变化，突出了其适应性的多功能性。基因组分析进一步确定了与氢化酶和硫氧化相关的途径。还将菌株TT6的表型和化学分类学特征与密切相关的模式菌株进行了比较，证实了其基因型和表型的独特性。提出了新物种sp. nov.，以TT6（=KCTC 82306 = JCM 34945）作为模式菌株。本研究强调了该属在农业和生态方面的重要性。
