Study On Antibacterial Components Of Endophytic Fungi From Eucommia Ulmoides

Eucommia ulmoides Oliv., the only variety in eucommia genus, eucommia family, is one kind of peculiar cash tree in our country. As one kind of plant in the second class which is protected in China, the resources of E. ulmoides need protection on the basis of full utilization. Hoping for not destroying E. ulmoides resources we have now and exploiting natural anti-biotic substances, our research group have isolated and identified endophytic fungi from E. ulmoides, tested antibacterial activity of some strains, isolated and elucidated four natural compounds from one of these endophytic fungi, and tested for antibacterial activity of 2 natural compounds. The results are as the follows:1 80 strains of endophytic fungi were separated from roots, stems, and leaves of E. ulmoides by tissue isolation method for the first time. 49 strains in 13 genuses were identified according to their morphological and micro-structure characters; Alternaria sp. and Fusarium sp. are dominant endophytic fungi population in E. ulmoides which occupy 47% in 49strains.2 Antibacterial activity of 49 strains endophytic fungi and of their secondary metabolites was tested with phytopathogentic fungi,mold,yeast and bacterium. DR11.1A1(Fusarium sp.)has inhibitive action to all tested phytopathogentic fungi,mold,yeast and bacterium according to analysis of activity results.3 DR11.1A1 strain was fermented in liquid culture medium, and extracted for its crude metabolites (21.2g). We got F1～F8 from the crude metabolites which were subjected to silica gel column.F2 and F3 were subjected to silica gel column, SephdexLH-20 column, chromatography thin layer and re-crystallization. 4 compounds were elucidated.4 MIC(minimum inhibition concentration) of compoundⅠandⅢagainst S. aureus, E. coli,B. cintrea,A. brassica,R. glutinis,Penicillium sp. were determined quantitively. Results showed that compoundⅠ,Ⅲhave inhibition effect on tested phytopathogentic fungi,mold,yeast and bacterium to a certain extent, and worth of further study.