杜仲内生真菌代谢产物对大肠杆菌的作用机理研究

Effects of the metabolites of an endophytic fungi from Eucommia ulmoides Oliv on E. coli

从杜仲中筛选出一株具有较好抑菌活性的内生真菌Y18,并探讨了其代谢产物对大肠杆菌的作用机理。采用流式细胞仪和傅里叶变换红外光谱仪等研究了内生真菌Y18代谢产物对大肠杆菌细胞膜、全细胞蛋白质以及核酸结构等的影响。结果显示:用Y18代谢产物处理后的大肠杆菌细胞膜的通透性增强,全细胞蛋白质和核酸结构发生变化。处理4h后,大肠杆菌菌液相对电导率为16.22%,PI阳性细胞的比例达到25.31%;蛋白结构变化主要是β折叠增加,由处理前的34.60%增加到41.47%。α螺旋、无规卷曲、β转角结构均有降低,其中,无规卷曲由21.80%下降到18.67%,下降最为明显;核酸物质结构也发生了明显变化。

An endophytic fungi strain Y lS,the metabolites of which had good antimicrobial activities,was isolated from Eucommia ulmoides Ofiv and the antimicrobial mechanism of its metabolites was also studied.The effects of the metabolites of the endophytic fungus strain Y18 on Ecofi cell membrane and the structure of the protein and DNA were studied by flow cytometry（FCM） and fourier transform infrared spectroscopy （ FT- I R）. Results showed that, after the treatment of the metabolites,the cellular membrane permeability of E coil cells was increased and the structure of the protein and DNA were changed.The relative electric conductivity of E. coil was 16.22% and the percentage of Pi-stained E.coli reached 25.31% after 4 hours. The LS-fold structure increased from 34.60% to 41.47%. Meanwhile the proportion of co-helix, random coil and β-turn reduced.Among them, the random coil structure dropped obviously from 21.80% to 18.67%. The structure of nucleic acid materials had also been changed.