碱宁,紫草素及其衍生物(A/S)是紫草科某些植物的根中产生的次生代谢产物,例如紫草红藻Siebold&Zucc。和Alkannatinctoria(L.)陶施。这些萘醌表达抗癌,伤口愈合,和抗菌活性。为了研究从A.tinctoria分离的内生细菌与抗菌药物A/S之间的相互作用,筛选已知对化合物具有抗性的内生细菌对液体培养基中的A/S的影响。此后,菌株假单胞菌。选择R-72008并测试其在营养培养基和以A/S作为唯一碳源的基本培养基中修饰A/S的能力。记录细菌生长,进行高效液相色谱-二极管阵列和超高效液相色谱-电喷雾电离质谱分析以检测和定量代谢物。在用R-72008接种的营养培养基中,观察到最初存在的A/S单体的量的减少,并且与A/S低聚物的增加相关。此外,基本培养基中初始A/S单体的显着减少与细菌生长有关,第一次显示细菌菌株,假单胞菌。R-72008能够使用萘醌A/S作为唯一碳源。这项研究为细菌和植物抗菌剂之间的相互作用开辟了新的视角。
Alkannin, shikonin and their derivatives (A/S) are secondary metabolites produced in the roots of certain plants of the Boraginaceae family such as Lithospermum erythrorhizon Siebold & Zucc. and Alkanna tinctoria (L.) Tausch. These naphthoquinones express anti-cancer, wound healing, and antimicrobial activities. To study the interactions between endophytic bacteria isolated from A. tinctoria and the antimicrobials A/S, endophytic bacteria known to be resistant to the compounds were screened for their effect on A/S in liquid medium. Thereafter, the strain Pseudomonas sp. R-72008, was selected and tested for its ability to modify A/S in nutrient medium and minimal medium with A/S as sole carbon source. Bacterial growth was recorded, and high performance liquid chromatography-diode array and ultra-high performance liquid chromatography-electrospray ionization-mass spectrometry analyses were performed to detect and quantify metabolites. In nutrient medium inoculated with R-72008, a decrease in the amount of A/S monomers initially present was observed and correlated with an increase of A/S
oligomers. Moreover, a significant decrease of initial A/S monomers in minimal medium was correlated with bacterial growth, showing for the first time that a bacterial strain, Pseudomonas sp. R-72008, was able to use the naphthoquinones A/S as sole carbon source. This study opens new perspectives on the interactions between bacteria and plant antimicrobials.