深海独岛枝芽胞杆菌1A00493杀根结线虫活性物质研究

Nematicidal Active Substance Produced by Deep-Sea Virgibacillus dokdonensis 1A00493

以一株具有杀南方根结线虫(Meloidogyne incongnita)活性的深海独岛枝芽胞杆菌(Virgibacillus dokdonensis)1A00493为研究对象,对其发酵上清液的杀线虫活性进行测定,并对杀线虫活性物质进行理化分析。利用正相硅胶柱、反相硅胶柱、LH-20葡聚糖凝胶柱分离以及示差折光高效液相色谱(RID-HPLC)对活性物质进行分离纯化,将纯化的活性物质进行液相色谱-质谱联用分析。结果表明,杀线虫活性物质耐高温、对蛋白酶和酸碱不敏感、硫酸铵沉淀物无杀线虫活性、3kDa超滤管滤过液有活性、易溶于甲醇和氯仿,推测活性物质是中强极性小分子物质。杀线虫活性物质主要有3种化合物,其中分子量为234Da的新型化合物很有可能是主要的活性物质。

A deep-sea Virgibacillus dokdonensis 1A00493, which had nematicidal activity against Meloidogyne incongnita, was taken as the research object. The nematicidal activity of fermentation supernatant was de- termined,also the physical and chemical analyses on nematicidal active substance were carried out. The crude extracts of fermentation supernatant were isolated and purified by a positive silica gel column, followed by a re- verse silica gel column,a Sephadex LH-20 gel column and RID-HPLC. Results showed that, nematicidal active substance was insensitive to high temperature,protease and pH value, ammonium sulfate precipitation had no nematicidal activity,the supernatant filtered through a 3 kDa ultrafiltration tube remained active,and it was easily soluble in methanol and chloroform. It is speculated that the active substance is a moderate polarity com- pound with small molecules. The results of LC-MS show that,the nematicidal active substance most likely con- tain three compounds,and the active substance molecular weight may be 234 Da.