扁枝槲寄生提取物对金黄色葡萄球菌抑菌机理的研究

本论文主要研究了95%乙醇扁枝槲寄生提取物的抑菌效应,并研究了抑菌机理。研究发现,95%乙醇扁枝槲寄生提取物对大肠杆菌、金黄色葡萄球菌、李斯特杆菌、铜绿假单胞菌、鼠伤寒沙门氏菌及变异微球菌均有明显抑菌效果,对枯草芽孢杆菌和纳豆芽孢杆菌无明显作用,对金黄色葡萄球菌抑菌效果最好(最低抑菌量为0.1 mg/m L)。进一步研究发现,提取物可增加金黄色葡萄球菌的细胞壁及细胞膜的通透性,引起细胞内含物如可溶性糖类、蛋白质等外泄,导致电导率上升。光学显微镜、扫描电镜以及透射电镜观察证实了提取物不仅能作用于菌体的壁膜系统,破坏菌体细胞的正常结构,还能通过抑制细胞分裂等方式来杀灭菌体。本文研究结果表明扁枝槲寄生具有开发成天然食品添加剂的良好前景。

Antimicrobial Mechanisms of Mistletoe (Viscum articulatum) Extracts Against Staphylococcus aureus

The antibacterial effects and mechanisms of 95% ethanolic extracts of Viscum articulatum were studied. The result showed that 95% ethanolic extracts of mistletoe had significant antagonistic activity against Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, Pseudomonas aeruginosa, Salmonella typhimurium, and Micrococcus varians and had no effect on Bacillus subtilis and B. natto. The best antibacterial effect was observed in controlling Staphylococcus aureus (minimum inhibitory concentration (MIC): 0.1 mg/mL). Further studies showed that 95% ethanolic extracts increased the permeability of bacterial cell walls and membranes and caused the leakage of cellular contents such as soluble saccharides and proteins, thus increasing the conductivity. The observations from light microscopy, scanning electron microscopy, and transmission electron microscopy further demonstrated that the extracts could not only target the bacterial cell wall and membrane systems to destroy their normal structures, but also killed bacteria by inhibiting cell division. The results suggest that Viscum articulatum presents potential as a natural food additive.