An Endophytic Actinomycetes From Camellia Sinensis And Screening Of Its Antifungal Metabolites

The main contents of this study are as follows:1. The identification of BF-01 using morphological characters and the partial sequence of its 16SrDNA.2. The determination of the inhibition spectrum of strain BF-01.3. The extraction and purification of antimicrobial compounds.The main results of this study are as follows:1. BF-01 strain isolated from colony of endophytic fungi Guignardia mangiferae which was isolated from tea plant C. sinensis cultured at 28℃for 30-40d. It was identified as Streptomyces according to its morphological and spores chains characters through scan electron micrograph.We sequenced the 16SrDNA of BF-01, and cluster result of 16S rDNA sequence analysis showed that the strains BF-01 in the same branch with Streptomyces cavourensis in evolutionary tree. BF-01 strain was tentative identified as Streptomyces cavourensis according to its morphological characters and molecule characters.2. The inhibition to some fungi, bacteria and spores germination. (1) The result of the dual culture inhibition test showed great effect to the tested seven endophytic fungi and seven pathogenic fungi. The maximum antifungal rate was higher than 90% to TN15, TN5, TN13 and TN2-2; (2) The result of fermentation inhibition test showed inhibition affection to 13 strain but Trichoderma viride. (3) The inhibitory of extraction to pathogenic bacterium and Monilia albican showed great affection, SPSS analysis showed great significant and significant effects. Generally, BF-01 strain has a broad inhibition spectrum. (4) The inhibition rate of extraction on germination of Fusarium gramimearum and Fusarium stoveri showed great affection, the germination decreased with the extraction increased, the inhibition increased.3. The fermentation were first purified through alcohol precipitation, extracted by chloroform, determined by GF254,and chromatographer by silica column, four activity component were found, componentⅡ,Ⅲ,ⅣandⅧ. The componentⅧ2 showed antibiosis after further Sephadex LH-20 column chromatography. By GC-MS analysis, two compound were found,2-Methy1 -4-ethoxycarbonyl-3H-imidazo[1,5-b] pyridazine-5,7-(6H)-dione named compound A, and 1-Phenyl-3-(2-pyridyl)-5-pyrazolon named compound B. They were alkaloids and heterocyclic which had similar structure. The two structures had been largely reported,and had great application of pesticides and pharmaceutical.