可口革囊星虫体腔液白细胞抗菌物质的活性及理化特性

Antimicrobial activity and physicochemical properties analysis of leukocyte antibacterial substances from Phascolosoma esculenta

采用离心法分离可口革囊星虫(Phascolosoma esculenta)体腔液白细胞,经乙酸透析法抽提,以琼脂径向扩散对抽提物质的抗菌活性进行测定,用扫描电镜观察等方法对可口革囊星虫白细胞抗菌活性物质的抗菌机理进行分析,采用酸性聚丙烯酰胺凝胶电泳(A-PAGE)技术对体腔液抗菌物质进行初步分离。结果表明:可口革囊星虫体腔液白细胞中具有广谱抗菌活性物质,对大部分革兰氏阳性菌、革兰氏阴性菌、真菌具有广谱高效抑菌活性,并且该物质的抗菌活性对高温具有较强耐受性;酶活性检测发现抗菌活性物质具有一定的蛋白酶但不具有溶血特性;扫描电子显微镜观察发现经过抗菌物质处理过的细菌和酵母的细胞壁粗糙,有些细菌表面出现孔洞;经A-PAGE电泳分离及琼脂径向扩散结果显示,可口革囊星虫体腔液白细胞抽提物中至少存在两种不同的抗菌活性成分,是一种抗菌活性成分较复杂的混合物。研究表明,可口革囊星虫体腔液中存在广谱且耐高温的抗菌活性物质,该物质具有一定的应用前景。

The blood cells of Phascolosoma esculenta were separated by conventional centrifugation.The leukocyte cells in its coelomic fluid were extracted by acetic acid dialysis,and the antibacterial activity of the extracted substances was determined by agar radial diffusion.The antibacterial mechanism of leukocyte antibacterial substances in the coelomic fluid of P.esculenta was analyzed by scanning electron microscopy and the antibacterial substances in the coelomic fluid were preliminarily separated by acid polyacrylamide gel electrophoresis(A-PAGE).The results showed that there was a broad-spectrum antimicrobial activity substance in leukocytes of P.esculenta coelomic fluid,which had broad-spectrum and high-efficiency antimicrobial activity against most Gram-positive bacteria,Gram-negative bacteria and fungi,and the antimicrobial activity of this substance was highly resistant to high temperature.Enzyme activity test showed that antimicrobial substances had certain proteases but no hemolytic characteristics;scanning electron microscope observation showed that the cell walls of bacteria and yeast treated with antibacterial substances were rough,and holes appeared on the surface of some bacteria.The results of A-PAGE electrophoresis separation and agar radial diffusion preliminarily showed that there were two different antimicrobial active substances in the extract of P.esculenta.It was showed that there was a broad-spectrum and high-temperature resistant antibacterial active substance in the coelomic fluid of P.esculenta,which had a certain application prospect.