不同培养基及诱导物对捕食性真菌Duddingtonia flagrans发酵液中蛋白质的产生及杀虫作用的影响

为研究捕食性真菌Duddingtonia flagrans发酵液中蛋白质的产生及杀虫作用,使用不同营养成分组成的液体培养基及诱导物,对Duddingtonia flagrans进行培养和诱导,测定其发酵液中的蛋白质含量、蛋白酶活性、磷酸酶活性和杀虫作用,进而确定Duddingtonia flagrans产生胞外蛋白质和杀虫作用最适的培养基与诱导物。结果显示,不同培养基及诱导物对Duddingtonia flagrans的代谢过程会产生明显影响,导致其分泌的蛋白质种类、浓度以及蛋白酶和磷酸酶的活性显著不同;Duddingtonia flagrans发酵液不仅具有杀线虫活性,而且有杀蝇蛆作用。上述结果为进一步研究捕食线虫性真菌的杀虫机理提供了重要参考依据。

Effects of varied cultures and inductors on production of proteins and toxicity to nematodes or insects in the broth filtrate of Duddingtonia flagrans

To study the production of proteins and toxicity to nematodes or insects in the broth filtrate of the nematode-trapping fungus,different liquid media with varied nutritional ingredients and inductors were used to culture Duddingtonia flagrans.The fermentation broth filtrations were collected,and the protein content,protease activity,alkaline phosphatase activity and toxicity of the broth filtration to nematodes or insects were evaluated to determine the best medium and induction agent for producing exoproteins and toxic substance to nematodes or insects.The results showed that different media and induction agents could significantly influence the metabolic process of D.flagrans,and it led to vary the types,concentration,activity of proteins and the phosphatase activity.Moreover,we also found the fermentation broth of D.flagrans not only had nematicidal activity,but also had a role to kill the fly larvae.The results above provided an important information for further studying the mechanism of nematode-trapping fungus to killing its prey.