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为明确拮抗菌枯草芽孢杆菌B43菌株拮抗香蕉枯萎病菌4号小种(Fusarium oxysporumf.sp.cubense race 4)的能力及其抑菌活性物质的性质,采用平板对峙法进行抑菌谱试验;酸沉淀、有机溶剂萃取法提取B43菌株中的抑菌活性物质并测定稳定性;根据脂肽类抗生素合成相关基因序列对B43基因组进行PCR扩增检测,运用LC-MS对粗提物进行成分分析。结果表明,B43菌株对21株植物病原真菌均有较好抑菌活性;酸沉淀法粗提物具有较好的耐热及耐紫外线特性,但不耐强酸强碱;通过特异性引物PCR检测,B43菌株基因组中含有srfAB、ituA、ituB、ituD、fenD、yndJ、sfp、mycB、lpa-14或fenB等脂肽类合成相关基因;LC-MS分析发现粗提物中含有Surfactin、Iturin、Mycosubtilin、Bacillomycin和Fengycin 5类脂肽类抗生素的同系物24种,说明该菌株可能能够产生多种脂肽类抗生素。
To determine the antagonistic ability of Bacillus subtilis B43 to Fusarium oxysporumf.sp.cubense race 4 and the properties of its antibacterial active substances, the antibacterial spectrum was tested by plate confrontation method. Acid precipitation , And the antibacterial active substance in B43 strain was extracted by organic solvent extraction method and the stability was determined. The B43 genome was amplified by PCR according to the sequence of lipopeptide antibiotic synthesis, and the crude extract was analyzed by LC-MS. The results showed that the B43 strain had good antibacterial activity against 21 plant pathogenic fungi. The acid precipitation method crude extract had good heat and UV resistance, but was not resistant to strong acid and alkali. By specific primer PCR, The genome of B43 strain contains related genes for the synthesis of lipopeptides such as srfAB, ituA, ituB, ituD, fenD, yndJ, sfp, mycB, lpa-14 or fenB. The crude extract contains Surfactin, Iturin, Mycosubtilin, 24 of the homologues of Bacillomycin and Fengycin 5 lipopeptide antibiotics, indicating that the strain may be able to produce a variety of lipopeptide antibiotics.