昆虫病原线虫共生菌YL001细胞内代谢产物抑菌作用研究初报

以生物活性跟踪法测定了菌株代号为YL001的昆虫病原线虫共生菌Xenorhabdus nematophilus细胞内代谢产物的不同溶剂提取物及其不同馏分的抑菌活性。结果表明,YL001细胞内代谢产物的乙醇提取物和甲醇提取物的抑菌活性均高于石油醚提取物、乙酸乙酯提取物和正丁醇提取物,前两种提取物对番茄灰霉病菌Botrytis cinerea和辣椒疫霉病菌Phytophthora capsici的72 h菌丝生长抑制作用最强,在0.4 mol/mL浓度时抑制率均达100％。乙醇提取物经硅胶柱层析分离,洗出液合并后收集得到8个馏分。测定了各馏分对番茄灰霉病菌菌丝生长的抑制作用,结果表明:馏分F6的抑菌活性最高,在0.5 mol/mL浓度时,96 h的菌丝生长抑制率可达96.09%;提取物的活性段主要集中在馏分F6、F7和F8。活体组织法测定结果表明,其乙醇提取物在10 mg/mL的剂量下对番茄灰霉病的保护效果为64.81%,治疗效果为62.03%。

Study on the Antifungal Activity of Intracellular Secondary Metabolic Products from Xenorhabdus nematophilus

The fungicidal activities of extracts and fractions from Xenorhabdus nematophilus,code named YL001 cells were tested in vitro and in vivo.The bioassay results indicated that fungicidal activity of ethanol extract and methanol extract was higher than that of other extracts.The ethanol extract was subjected to chromatography silica gel(200~300 mesh)using CHCl_3-methanol with increasing amounts of methanol.The resulting 8 fractions with different hydrophobicities were analyzed by in vitro antibacterial activity assay to Botrytis cinerea.The result showed that fraction 6 was more active than others and the inhibition rate against the mycelial growth of Botrytis cinerea was 96.09% after 96 hours.The result also indicated that fungicidal components were mainly in fraction 6,fraction 7 and fraction 8.In(addition),protective effect and therapeutic effect of the cells products at 10 mg/mL against the Botrytis cinerea were 64.81% and 62.03% on tomato,respectively.