【摘要】 菌株xjy是一株从新疆棉田土壤中筛选出的对番茄叶霉病菌(Fulviafulva)有较强拮抗作用的放线菌,其对23种常见植物病原真菌和6种细菌有较好的抑制效果,抗菌谱广。其形态特征、培养特性、生理生化特性、细胞壁组分与放线菌中的淡紫灰链霉菌(Streptomyces lavendulae)相同,16SrDNA序列同源性达99.6%。研究发现该菌的摇瓶发酵配方和培养条件为:大豆粉2%、葡萄糖2%、NaCl0.8%、CaCO30.2%、(NH4)2SO40.32%,起始pH7.0、28℃、180r/mim、摇瓶培养6d,这些结果为该菌株今后的应用、抗生素的分离提纯和产业化提供了实验依据。更多还原

【Abstract】 An actinomycete strain xjy was isolated from the soil of cotton field in Xinjiang against pathogenic fungus Fulvia fulva. The growth of 23 plant pathogens and 6 bacteria were strongly inhibitded by strain xjy on PDA plate. Antimicrobial spectrum of fermentation filtrate of strain xjy is extensive and selective to different pathogens. The morphology,cultural characteristics,physiological and biochemical properties,chemotaxonomy and 16S rDNA sequences of this strain were studied. The strain showed faint yellow vegetative mycelium,spiral spore-bearing filaments and column spores with smooth surface. No pigment was produced in culture. The cell wall typeⅠ and sugar type C showed the strain with streptomyces character. A phylogenetic tree was constructed by comparing with the published 16S rDNA sequences of the related species and showed 99.6% identity of nucleotide sequence of 16S rDNA with Streptomyces lavendulae. From the polyphasic taxonomical view,the strain xjy falls into Streptomyces lavendulae. The optimum fermentation condition of strain xjy for producing the most effective ferment filtrate were cultured in 2% soybean flour,2% glucose,0.8% NaCl,0.2% CaCO₃,0.32% （NH₄）₂SO₄,the initial pH of 7.0,at 28℃ and shaked at 180r/mim for 6d. These results are valuable to strain application,antibiotics purification and its industrialization.更多还原