Study On The Isolation, Fermemetation And The Metabolite Of Soil Actinomycetes

In this study, 130 strains of actinomycetes were isolated from 80 soil samples which collected from various areas in the south-wei dry plateau.One genetically stable actinomycetes strain S-159-05was selected after comparison on inhibition activity of pathogenic fungi by means of selected in solied culture and fermental filtrate. In order to improve the efficiency of isolating actinomycetes from soil and solve the problem of contamination by bacteria and fungus when actinomycetes isolated and cultivated, the effect of K2Cr2O7, actidinoe, nystatin and curbenduzim on bacteria, fungus and actinomycetes was studied in this article. The result showed that K2Cr2O7 had distinct inhibition effect on soil fungus and bacteria, which can stimulates the growth of some actinomycetes, is a high effect, convenient and cheap inhibitor.The optimum fermentation medium of S-159-05 was screened on the base of NMM, and it was composed of glucose 1%, starch 1.5%, peanut powder 2%,CaC03 0.25%,K2HPO4 0.05%.The optimum fermentation condition which can produce the most effective fermental filtrate was 72 hour for rotational culture time,pH 8.0 of medium,30-34℃,rotational velocity is 150r/min.The crude active-product of S-159-05 has a wide-range of inhibition. 1mg/l materials has an inhibition efficiency above 45% against Pyricularia oryzae,Bipolaris sorokiniana,Botrytis cirerea,Alternaria alternata and Erwinia carotovora et al.The avtive product was isolated and purified,it was a mono-component,named An-2.The physico-chemical property was studied:it was soluble in water ,methyl alcohol ,ethyl alcohol and insoluble in acetone,ether,ethyl acetate,benzene,chloroform,petroleum etc. UVmax is 316nm;melt-point is 241-244℃; According to the physical and chemical properties as well as the UV , IR, 1H-NMR, and Mass spectrums,It was classified to glucoside-containing antibiotic family.The inhibiting range and mechanism of the active product of S-159-05 was studied. The result showed that the active product of S-159-05 has a strongly inhibition of the mycelia growth and spore germination which lead to the mycelia twisted and inflated, the abnormal branching increased, the mycelia wall broke and the material of the cell let out, the spores was reduced and deformation. The rate of germination and length of the tube was decreased. The active product of S-159-05 not only can prevent the invasion of Botrytis cirerea mycelia,and has a good control efficacy, showed a good curing efficacy.