Isolation,Characterization And Antioxidant,Antifungal Activity Of Endophytic Fungi From Hosta. Ventricosa

In this paper,the endophytic fungi were isolated and characterized from the roots of Liliaceae Hosta.And the antioxidant activities of their crude extracts were investigated by T-AOC,DPPH and ABTS⁺methods,while the antifungal activities of their fermented liquid against Sabouraudites lanosus,Microsporum gypseum,and Trichophyton mentagrophytes were mearsured by the mycelial growth rate method.After that,the optimization of fermentation for the active strain and the screening of antifungal polarity parts were tested.The results were as follows:1.Thirteen kinds of endophytic fungi were isolated from the roots of Hosta.Ventricosa.They were classified into six genera by molecular biological identification,among which,7strains,accounting for 53.84%,belonged to the dominant species,the Fusatium.2.The ethanol extracts from the thirteen kinds of the endophytes showed different antioxidant activities.Among which,the ethanol extracts from Ho V1 and Ho V4 exhibited stronger comprehensive antioxidant activities,with higher T-AOC values（63.46±0.26 U/g and 66.05±0.71 U/g,respectively）,lower EC₅₀ values against DPPH radicals（83.42±0.24μg/m L and 59.13±0.78μg/m L,respectively）and ABTS⁺radicals（30.25±0.05μg/m L and24.66±0.65μg/m L,respectively）.Meanwhile,the ethanol extract from Ho V8 showed excellent scavenging activity against DPPH radicals(EC₅₀=16.02μg/m L),better than BHT.By the way,the ethanol extracts from Ho V1 and Ho V4 presented higher phenol levels（1.78±0.01 mg/g and 2.38±0.04 mg/g,respectively）,which may contribute to their better antioxidant activities.Otherwise,the lower level of phenol contents in the ethanol extract from Ho V8 may not the only source for its antioxidant activity.3.Four kinds of the broth from Ho V1,Ho V3,Ho V7 and Ho V11 showed better broad-spectrum antifungal activities than others.Especially the broth of Ho V3 and Ho V7 presented higher antifugal activities,which were in higher steroid levels（5.63 mg/g and 5.37 mg/g,respectively）.It implied that their antifungal activities may mainly caused by their steroid constitutes.4.Taking antifungal activities of the broth and the mycelium weight as comprehensive indicators,the fermentation optimization was carried out.The results showed that the optimal fermentation condition was lactose content（13%）,peptone content（10%）and p H 8.5.Four different polarity extracts were prepared from the broth of Ho V7 by gradient extraction.The antifugal tests showed that only the chloroform extract and water layer with higher steroid levels（120.15 mg/g and 91.14 mg/g,repectively）presented broad-spectrum antibacterial activities,in which the MIC values of chloroform layer were lower than that for the later.The activity of chloroform extract aginst microspore canine was remarkable with MIC value 312.5μg/m L.