Isolation Of Actinomycetes From Soil In Inner Mongolia Of China And Agroactivity Of Fermentation Products Of Actinomycetes

With the seclective methods,183strains were obtained, which isolated from soil infarming, sand, colliery, saline-alkali and Wetlands in inner monolia.The screening onagricultural activity of the fermentation products of actinomycetes had been carried on. Themain results are below.Biopsy method and growth rate method were used to screen fungicidal activity offermentation broth of183strains against Botrytis cinerea and Fusarium oxysporumf.sp.Cucumerinum. The results showed that the strains numbered12-09-11and12-09-4showed high activity against B. cinerea in vivo, and control effect is92.91%and92.09%.System antibacterial activity testing showed that12-09-4and12-09-11exhibited wideantibacterial spectrum and strong antibacterial activity. The fermentation broth of12-09-4and12-09-11exhibited well activity on mycelium against sclerotinia sclerotiorum, Exserohilumturcium, and B. cinerea, and the inhibition rate were all above90%.12-09-4and12-09-11showed a certain inhibitory activity on spore germination against Exserohilum turcium,Alternaria alternate, F. oxysporum f.sp.Cucumerinum, and B. cinerea, and the inhibition ratewere all above75%, The most noteworthy is that the inhibition rate were above95%againstF. oxysporum f.sp.Cucumerinum, and B. cinerea. The results of spore germination inhibitionindicated that the fermentation broth of12-09-11and12-09-4exhibited high inhibitionactivity against B. cinerea and F. oxysporum f.sp.Cucumerinum, and EC50of sporegermination inhibition were0.0936mg/mL,0.1092mg/mL,0.2163mg/mL,0.2429mg/mL.The results of pot showed that fermentation broth of12-09-11and12-09-4exhibited wellprotective efficacy, and the control effect were76.95%and72.67%, but the therapeuticefficacy was only50%.Strains with insecticidal activity were screened from183actinomycetes which wereisolated, and Artemia Salina with I nauplii were used for the tested objects. The resultsshowed that the fermentation broth of23strains exhibited a certain toxic activity, on this basis,3rdLarvae of Culex pipiens pallens were used for tested objects to further screening from thefermentation broth of23strains. The results showed that the toxic activity of three strainsagainst3rd larvae of Culex pipiens pallens were all above90%after12h, the three strains named11-09-3,11-09-49and12-09-10. Tetranychus cinnabarinus,3rdPlutella xylostella and3rdMythimna separate were used for tested objects to fourthly measure insecticidal activity offermentation broth of11-09-3,12-09-10and11-09-49. Mortality of fermentation broth of11-09-3,12-09-10and11-09-49against Plutella xylostella were96.67%,90.00%and65.49%after48h. And against Tetranychus cinnabarinus were93.10%,86.67%and88.67%after12h.The rusults showed that the EC50of11-09-3and12-09-10were18.89mg/mL and22.7489mg/mL.Insecticidal activity of crude extract broth of11-09-3showed that crude extract broth inbutanol phase exhibited a higher cytotoxic activity (92.34%). The testing of stability of activesubstances in fermentation showed that temperature and pH has a great influence on secticidalactivity. The results of optimization of fermentation conditions of insectidal activity of11-09-3showed that fermentation broth of11-09-3exhibits the best insecticidal activity in thecondition of that the amount of bottling of medium was125ml, the fermentation teme was5d, initial pH was7.5, fermentation temperature was30℃, and inoculation amountfor20%0fthe amount bottling, and in the basis of millet liquid medium.