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为明确生防菌株Bacillus subtilis SN-02产生的抑菌物质的种类和组成,对其进行分离、纯化及结构测定。发酵滤液经盐酸沉淀,有机溶剂提取,薄层层析显色分析,初步确定该活性物质是一种具有闭合肽键的脂肽类物质。经Pharmadex LH-20精制后得到纯度为95.7%的淡黄色结晶状物质,液质联用检测到活性成分是分子量为1080、1035和1021D的生物表面活性素。紫外吸收光谱表明该物质在210nm处有吸收峰,红外吸收光谱证实该分子的亲水基是一条肽链,疏水基部分是一脂肪酸分子,且为一种环状脂肽类物质。氨基酸分析表明该活性物质由4种氨基酸组成,且4种氨基酸的摩尔比为Glu∶Leu∶Val∶Asp=1∶4∶1∶1。
In order to clarify the species and composition of bacteriostasis substances produced by Bacillus subtilis SN-02, its isolation, purification and structure determination were carried out. The fermented filtrate was precipitated by hydrochloric acid, extracted with organic solvent and analyzed by thin layer chromatography. It was initially determined that the active substance was a lipopeptide with closed peptide bonds. After purification by Pharmadex LH-20, a pale yellow crystalline substance with a purity of 95.7% was obtained. LC-MS analysis showed that the active ingredient was a biosurfactant with molecular weights of 1080, 1035 and 1021D. UV absorption spectrum showed that the substance had an absorption peak at 210 nm. The infrared absorption spectrum confirmed that the hydrophilic group of the molecule was a peptide chain, the hydrophobic moiety was a fatty acid molecule, and it was a cyclic lipopeptide. Amino acid analysis showed that the active material consisted of four kinds of amino acids, and the molar ratio of the four kinds of amino acids was Glu: Leu: Va: Asp = 1: 4: 1: 1.