Preliminary Study On Isolation And Identiifcation And Biological Activities Of Antibacterial Endophytic Fungi From Gynostemma

56strains endophytic fungi which were5orders,6families,8genera throughmorphological identification had been isolated from Gynostemma pentaphyllum in this study.To have morphological observation and ITS5.8s rDNA sequence identification for strainsJY25which had bacteriostasis activity, the results showed that endophytic fungi JY25fromgynostemma pentaphyllum was Deuteromycotina, HyPhomycetes, Tuberculariales,Tuberculariaceae, Fusarium sp.Gynostemma pentaphyllum endophytic fungi JY25was optimized by Staphylococcusaureus and Escherichia coli as the indicator bacteria. The results showed that antibacterialproduction of fungi JY25was promoted by added1%gynostemma pentaphyllum juice infermentation medium, the bacteriostatic circle diameter was14.89mm for E. coli byoptimized, which was higher of62.73%than the fermentation medium was not optimized; thebest fermentation condition of JY25was determined by orthogonal test, that was loaded liquid100mL/250mL, inoculation amount3%, temperature28℃, rotate speed160r/min,fermentation time9d, the bacteriostatic circle diameter were16.5mm and30.3mm for E.coli and Staphylococcus aureus by optimized, which were higher of4.2mm and4.0mm thanthe fermentation medium was not optimized.The acid-base stability, thermal stability and protease K sensitivity of antimicrobialsubstances which was produced by gynostemma pentaphyllum fungi JY25were researched,the results showed that the bacteriostatic effect of antimicrobial active substances for E. coliwas well by pH3.0~7.0, and the bacteriostatic effect of antimicrobial active substances forStaphylococcus aureus was well by pH5.0~9.0; antimicrobial active substances showed thegood thermal stability in the scope of30~90℃; antimicrobial active substances was notsensitive to proteinase K. Gynostemma pentaphyllum endophytic fungi JY25fermentationbroth and gynostemma pentaphyllum leaching juice component were identified, the resultsshowed that the fungi JY25fermented liquid contained organic acids, hydroquinone and sapogenin, besides polysaccharide and flavonoids which were same as the active ingredientthe host plants contained. The antibacterial activity substances of fungi JY25fermentationbroth to Staphylococcus aureus and E. coli mainly existed in the ethyl ether gathers in moreand ethyl acetate extract phase.Antibacterial mechanism of gynostemma pentaphyllum endophytic fungi JY25wasresearched, the results of the study showed that the active substances of fungi JY25made themetal ions in the cell ooze through affecting the Staphylococcus aureus and E. coli cellmembrane permeability, affected the protein synthesis of indicator bacteria, the growth ofindicator bacteria was inhibited in the Exponential phase, and deformation of the bacteria.The anti-cancer and antioxidant test by antibacterial material of gynostemmapentaphyllum endophytic fungi JY25showed that the crude polysaccharide of thepolysaccharides extract form fungi JY25fermentation broth, spores grinding coolant andgynostemma pentaphyllum leaching juice that the concentration were20mg/mL were1.453,0.357and1.372mg/mL;5mg/mL of3samples total antioxidant capacity were14.06,3.45and4.56U/mL; the half to death IC50concentrations of3samples to lung cancer cells A549were0.088,0.304and0.385mg/mL.