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从土壤中分离得到一株抗菌活性菌株,通过16Sr DNA基因序列相似性和系统发育分析,发现该菌株为埃勒斯致病杆菌,并将其命名为埃勒斯致病杆菌SN22(Xenorhabdus ehlersii SN22)。利用硅胶柱层析结合凝胶柱层析技术,从埃勒斯致病杆菌SN22(X.ehlersii SN22)发酵液中分离得到化合物1,通过核磁共振波谱、质谱及X-光单晶衍射技术分析,鉴定其为3-(环己-2-烯)丙烯酸。文献调研发现,该化合物为新的天然产物,命名为Xenorhabic acid。采用菌丝生长速率法测定了该化合物对植物病原真菌的抑菌活性;采用微量稀释法测定了其对病原细菌的最小抑制浓度。结果表明:其对向日葵菌核病菌Sclerotinia sclerotiorum和瓜果腐霉病菌Pythium aphanidermatum菌丝生长具有明显抑制作用,其EC_(50)值分别为27.99和29.55μg/mL;对大肠埃希杆菌Escherichia coli的最小抑制浓度(MIC)为62.5μg/mL。
An antibacterial activity strain was isolated from soil. According to the sequence similarity and phylogenetic analysis of 16S rDNA, the strain was identified as pathogenic bacteria, and named as Xenorhabdus ehlersii SN22 ). Compound 1 was isolated from the fermentation broth of Xehlersii SN22 by silica gel column chromatography and gel filtration chromatography. The structure of compound 1 was analyzed by 1H NMR, MS and X-ray single crystal diffraction , Which was identified as 3- (cyclohex-2-ene) acrylic acid. Literature research found that the compound is a new natural product, named Xenorhabic acid. The mycelium growth rate method was used to determine the antibacterial activity of the compound against phytopathogenic fungi. The minimum inhibitory concentration of the compound on pathogenic bacteria was determined by the method of microdilution. The results showed that it had significant inhibitory effects on the mycelial growth of Sclerotinia sclerotiorum and Pythium aphanidermatum, and the EC 50 values were 27.99 and 29.55 μg / mL, respectively. For Escherichia coli The minimum inhibitory concentration (MIC) was 62.5 μg / mL.