Isolation And Antimicrobial Activities Of Endophytic Fungi From Needles Of Cedrus Deodara G

Endophytic fungi are great resources which could develop high efficiency pesticide without residuum because of producing new compounds. At present endopytic fungi are widely used in pharmaceutical and pesticide. This test separates and screens two activity strains N0₃and N06from the health needle of Cedrus deodara G. The activity strain has great inhibition to the common plant pathogenic. And then preliminary research the fermentation broth and mycelium. The test carries through optimizing the N0₃strain cultivation conditions. The main results as follows:1. Eleven endophyte isolates were obtained from healthy needles of Cedrus deodara. The experiment biological assay eleven endophyte antagonized six plant pathogens, Phytophthora capsici, Fusarium oxysporum, Cytospora mandshurica, Colletotrichum gloeosporioides, Venturia pirina and Fusarium graminearum. The result showed there were antagonism in the experiment, and the best activity N0₃strain against Phytophthora capsici, Fusarium oxysporum, and Cytospora mandshurica by a dual cultural method. The results of eleven endophyte against Staphylococcus aureu, Escherichia coli, Bacillus subtilis and Xanthomonas campestris by inhibition zone method demonstrated bacteriostatic activity being existed difference. And then N05strain against Bacillus subtilis had70.86%of100ug/ml streptomycin.2. The biometric test deal with the fermentation broths and mycelium by eleven endophyte fermenting experiment. The results of this test confirm the above ones. The inhibition rato of N0₃strain against Cytospora mandshurica reach to80.56%, and N06strain against Phytophthora capsici reach to80.74%. The inhibition of the methanol extract of mycelium reveal N0₃strain extract has high activity against different pathogenic bacteria.The activities research of different days of the N0₃strain fermented suggested that antifungal activity had been related to biomass of N0₃strain fermentation broth. 3. Biological characteristics researched different conditions in temperature, pH value, carbon and nitrogen sources, and cultural media. The results are as followed: The proper growth temperature of the strain N0₃was28℃. Strain N0₃grew well in the scope of pH5-9. In addition, the optimal carbon source of N0₃growth was xylopyranose while the optimal nitrogen source was peptone. Strain N0₃grew well on beef poly peptone agar medium. Single factor orthogonal experiment of the strain N0₃showed the optimal carbon source growth was soluble starch and the optimal nitrogen source was sodium nitrate. The result declared inorganic salt combination had lower influence in liquid fermentation cultivated. The final outcome of orthogonal test maltose, peptone and KCl⁺FeSO₄7H₂O+MgSO₄7H₂O combination fermented the strain N0₃had produced maximum bacteriostatic activity substance. The result of pot experiment showed the fermentation broth of the strain N0₃has protected tomato in57.14%for Fusarium graminearum, and28.8%in treatment function.