乳酸链球菌抗菌肽的分离纯化及生物活性检测

Separation,Purification and Biological Activity Detection of Antibacterial Peptide Produced by Streptococcus lactis

通过凝胶过滤层析及制备型高效液相色谱法,从乳酸链球菌发酵液中筛选分离出了具有广谱抗菌活性的物质,利用金黄色葡萄球菌(ATCC25923)、大肠杆菌(ATCC25922)、绿脓杆菌、枯草芽孢杆菌、耶尔森菌、粪肠球菌对该活性物质的抗菌谱及杀菌机理进行了研究。结果表明:经过分离纯化,得到的较纯的活性物质为乳酸链球抗菌肽,该物质除了对绿脓杆菌没有杀伤作用,对其他5种细菌均具有杀伤作用。透射电镜观察结果显示,金黄色葡萄球菌(ATCC25923)经抗菌肽处理后,细胞出现破损或肿胀,有部分细胞内容物外泄,并伴有细胞质稀释的现象,细胞膜界限模糊不清,细胞膜甚至完全溶解。由于细胞内容物外渗,最终导致菌体死亡。

This study aimed to separate and purify the Streptococcus lactis-antimicrobial peptides which had wide antimicrobial properties by gel filtration chromatography and HPLC.Staphylococcus aureus（ATCC25923）,Escherichia coli（ATCC25922）,Pseudomonas aeruginosa,Bacillus subtilis,Yersinia and Enterococcus faecalis were used to research the bactericidal mechanism and antibacterial spectrum of the Streptococcus lactis-antimicrobial peptide.The results showed that a species of Streptococcus lactis-antimicrobial peptides which had killing effects on all bacterial cells except Pseudomonas aeruginosa was obtained by separation and purification.The microporous structure of Staphylococcus aureus（ATCC25923） was observed by transmission electron microscopy when the Streptococcus lactis-antimicrobial peptide was added.The transmission electron microscopy results showed that the Streptococcus lactis-antimicrobial peptide caused the Staphylococcus aureus（ATCC25923） cells broken,swelling and leakage,accompanied cytoplasmic diluted,cell membrane boundaries blurred or even completely dissolved,and made them apoptosis ultimately.