大肠杆菌诱导家蝇抗菌物质的研究

目的　对家蝇体内的抗菌物质进行研究。方法　用大肠杆菌诱导家蝇三龄幼虫 ,采用抑菌圈法 ,对家蝇体内抗菌物质的诱导效果及其活性进行研究。以SDS PAGE法分离家蝇的抗菌蛋白。结果　诱导产生的家蝇抗菌物质其活力高峰出现于第 48h。诱导后第 48h血淋巴稀释 10 0倍 ,对大肠杆菌的致死率仍达 12 % ;其抗菌物质对动、植物病原菌有广谱的抗菌活性 ,同时 ,未经诱导的家蝇幼虫也具有抗菌活性。SDS PAGE电泳分析表明 ,外源诱导能增强原有抗菌物质的表达量 ,并能激活新的蛋白产生。结论　为进一步纯化和生化分析家蝇体内的抗菌蛋白提供了新的依据。

Studies on antibacterial substance from the haemolymph of Musca Domestica L induced by injection of Escherichia Coli

Objective To study the antibacterial substance from the haemolymph of Musca Domestica L(house fly). Methods The third instar larvae of the house fly induced by injection with E.coli was used in the investigations.The method of plate growth inhibition assay was used to study the induced effect and activity of antibacterial substance of the house fly. The method of SDS PAGE electrophoresis was used to isolate the antibacterial protein of the house fly. Results The highest peak of the antibacterial substance occurred after 48 hours . After 48 hours by injection of E.Coli,we diluted the house fly haemolymph induced 100 times with distilled water, the death rate of E.coli still amounted to 12% treated by antibacterial substance from the haemolymph. The antibacterial substance has broadspectrum antibacterial activity against several animal and plant pathogens. Meanwhile, the haemolymph fromnon induced third instar larvae of Musca domestica L. also has antibacterial activity. SDS PAGE electrophoresis reveals that foreign agent can enhance the expression of antibacterial substance and activate novel proteins. Conclusions These results provided new basis for further researches on purification and biochemistry analysis of the antibacterial protein of the house fly.