Fermentation Condition Of Actinomycetes Against Cylindrocarpon Destructans And Antagonistics Extraction

In the paper,one better antagonistic actinomycete strain 1A against Cylindrocarpon destructcms was screened from seven strains in our lab,and the test of the antifungal bioactivity,the optimization of fermentation condition,the extraction of active ingredient,physic-chemical properties of the crude product, and analysis of the functional groups of active ingredient were studied in the experiment,The results showed as follow.By inhibiting zones and plate pairing culture,seven actinomycete strains were screened firstly and secondly in the experiment,the results showed that six strains were antagonistic against Cylindrocarpon destructans,of them,the inhibiting effect of the strain 1A was the best.The fermentation broth of the strain 1A had better inhibiting effect against Cylindrocarpon destructans,Fusarium graminearum,Pyricularia grisea,Curvularia lunata,Exerohilum turcicum,Alternaria alteranta,Cladosporium cucumerinum,Colletotrichum coccldes, and Bipolaris sorokiniana.The effect of antibiotics production of the strain 1A on seven media was compared,the result indicated the medium G was the most suitable.The fermentation condition of the strain 1A was studied,the results showed that the corn powder and glucose,soybean powder and yeasts were the best complex sources of carbon and nitrogen.Adding inorganic salt in medium was beneficial to the production of antibiotics of the strain 1A.By the orthogonal experiments,the optimal fermentation medium components was identified,which was corn powder(3%),glucose(1%),soybean powder(2%),yeast(0.3%),KH₂PO₄(0.1%),CaCO₃(0.3%),NaCl (0.1%),and the most suitable culture condition was 28 hours strain age,six percent inoculum concentration, 30 mL liquid in 250 mL triangular flask,60 hours fermentation period,180 rpm,28℃and pH 7.By comparing the pretreatment method(acid treatment method and organic solvent treatment method) of fermentation broth,the result showed that the deposit was completely with organic solvent treatment method, and the loss rate of the effective ingredient activity was lower,so the organic solvent treatment method was used in the experiment.Through the solvent extraction,collecting the organic phase,concentration and decompressing,the yellow crude product(tentative nameTS08) was obtained after removing the organic phase.By comparing the pathogen inhibiting activity of the crude fermentation broth and trichloromethane saturated liquid of the crude product TS08,the result showed that the activity of the crude product was less affected by environment condition.The crude production TS08 had the best stability to the ultraviolet radiation,high and low temperature.The result of chromatography test proved the active ingredient of TS80 was the neutral,and was water soluble, which had stronger polarity.By the color reaction,the result indicated the active ingredient of TS08 contained unsaturated link.By apagoge experiment,the results confirmed the active ingredient was not the amino acid, polypeptide or protein;it could be sugar or indicant.