Study On Antimicrobial Effects And Active Components Of Endoph Ytic Fungi Isolated From Inula Helenium L.

The roots of Inula helenium L.is widely used to treat the symptoms of chest pain,abdominal pain,vomiting and diarrhea,trauma section and fetal irritability.While alantolactone and isoalantolactone are the major active compounds of this plant,and the alantolactone and isoalantolactone has been demonstrated biological efficacy,such as anticancer,antimicrobial and insect repellent activities.This indicates that endophytic fungi isolated from I.helenium plants are sources of novel antimicrobial and anticancer compounds.The aim of the present study was to screen for antimicrobial activity in endophytic fungi isolated from surface sterilized roots,stems and leaves of I.helenium plants.The fermentation broths of endophytic fungi were tested for antimicrobial activity by the paper disc diffusion method against Escherichia coli,Bacillus subtilis,Staphylococcus aureus and Candida anbicans.Among 32 endophytic fungi,2 isolates showed antimicrobial activity against all tested microorganism,2 isolates displayed antimicrobial activity against at least three tested microorganism,5 isolates displayed antimicrobial activity against at least two tested microorganism,and 2 isolates displayed antimicrobial activity against at least one tested microorganism.We have found that the antimicrobial effectivity of same endophytic fungal strain there was significant difference between the PDB medium and Gzapek-Dox liquid medium.Ten endophytic fungal isolates with antimicrobial activities was identified on the basis of morphological characteristics and sequences of the internal transcribed spacer(ITS)region.As the results,YIGZ-1 and YIGZ-3 as belonging to the Aspergillus tubingensis,YIJZ-2 and YIJZ-6 as belonging to the Thanatephorus cucumeris,YIJZ-3,YIJZ-5 and YIJZ-7 belonging to the genus Penicillium,and YIYZ-1,YIYZ-2 and YIGZ-2 were identified as Bjerkandera adusta,Alternaria infectoria and Cadophora luteo-olivacea,respectively.Methanol extracts from the fermentation broth and mycelia of endophytic fungi were prepared by ultrasound method,and the alantolactone and isoalantolactone in the extracts were determined by TLC and HPLC.The results demonstrated that the alantolactone produced by an endophytic fungus Aspergillus tubingensis YIGZ-3 and by I.helenium roots.