产细菌素乳酸菌的筛选及其纯化和稳定性研究

Screening bacteriocin-producing lactic acid bacteria and purification of bacteriocin and its stability

以大肠杆菌、金黄色葡萄球菌、藤黄微球菌、单增李斯特菌、枯草芽孢杆菌、志贺氏菌、沙门氏菌为指示菌,从30个健康婴儿的粪便中筛选得到1株具有广谱抑菌作用的菌株,经鉴定为乳酸乳球菌(编号F-6-B).该菌株的培养条件为:MRS培养基起始pH 6.0,30℃静置培养48h.将其发酵液经硫酸铵沉淀,Hitrap SPHP(GE)阳离子交换柱层析后,得到的样品通过Tricine-SDS-PAGE为一条带,相对分子质量为3 300～5 800之间.经不同酸、热处理,该细菌素仍具有较好的抑菌活性,表现出较好的热稳定性和广谱的活性pH值范围,对胰蛋白酶处理敏感性差.

One strain of bacteriocin-producing bacterium was isolated from feces of 30 healthy infants,using Escherichia coli,salmonellas Micrococcus Luteus Listera,bacillus subtilis,shigella,Staphylococcus aureus as indicate germs,and was identified as Lactococcus schleifer（number F-6-B）.The bacteriocin was obtained from the fermentation broth of culture by ammonium sulfate precipitation and ion-exchange chromatography of Hitrap SPHP（GE）.The molecular weight of the bacteriocin was 3 300-5 800 that determined by Tricine-SDS-PAGE.Treated with acid,heat and enzyme,the bacteriocin still had significant effects on bacteriostasis,exhibiting its better thermostability,a broad-spectrum pH range of activity and poor sensitivity to trypsin.