中文摘要：

Bifidocin A是由Bifidobacterium animalis BB04代谢合成的一种新型广谱高效细菌素。以革兰氏阳性的金黄色葡萄球菌为测试敏感菌，分析细菌素BifidocinA的最低抑菌浓度及不同质量浓度下的抑菌效果，并从敏感菌细胞形态与结构、细胞膜的通透性、细胞膜的完整性以及细胞膜质子移动势的变化4个角度分别探讨该细菌素的抑菌作用机制。结果表明，细菌素BifidocinA对金黄色葡萄球菌CVCC26112的最低抑菌浓度为0.058μg/mL，抑菌活性较强且存在浓度依赖性；并初步推测其抑菌作用机制是通过耗散细胞膜质子移动势，增加细胞膜通透性，形成孔洞，进而破坏细胞膜完整性，并最终瓦解细胞。

英文摘要：

Bifidocin A,produced by Bifidobacterium animalis BB04,is a novel bacteriocin with antimicrobial activity against a wide range of foodborne bacteria.The objective of this study was to investigate the antibacterial activity and mechanism of action of bifidocin A against Staphylococcus aureus.The minimum inhibitory concentration(MIC)of bifidocin A for Staphylococcus aureus CVCC26112was0.058μg/mL.Time-kill assays showed that bifidocin A effectively inhibited the growth of Staphylococcus aureus CVCC26112in a time-and concentration-dependent manner.Results also suggested that bifidocin A exerted its anti-Staphylococcus aureus effect through the dissipation of the cytoplasmic membrane proton motive force(PMF),increased membrane permeability,and the formation of cell membrane pores,leading to the destruction of membrane integrity and ultimately complete disintegration of the cells.