姜厚朴水提物对大肠杆菌和金黄色葡萄球菌的抑菌机理研究

姜厚朴水提物对大肠杆菌和金黄色葡萄球菌的

抑菌机理研究

李婷，杨舒然，陈敏，宋丽雅，何聪芬

（北京工商大学,北京市植物资源研究开发重点实验室，中国化妆品协同创新中心，北京 100048） 摘要：为了探讨姜厚朴水提物（GMB）对大肠杆菌和金黄色葡萄球菌的抑菌机理，试验对GMB作用下菌体形态结构、膜系统上离子通道的酶活力和能量代谢等方面进行了研究。结果表明，GMB对大肠杆菌和金黄色葡萄球菌的MIC分别为6.25、12.5 mg/mL。大肠杆菌胞外AKP酶和β-半乳糖苷酶吸光度值分别增加1.78和4.24倍，GMB作用4 h后电导率显著上升，膜上Na+K+-A TP酶活性从0.42增加到1.74 mg prot/mL，且为阴性对照的1.7倍；金黄色葡萄球菌体表出现囊泡状、不规则的突起结构，SDH酶活性、总A TP 酶活性和胞内蛋白质含量分别降低40%、23.4%和17.9%，且AKP酶活和电导率均有所增加。由此推测出GMB主要是通过破坏大肠杆菌细胞壁、膜结构，增加其渗透性和通透性，造成胞内物质外流和蛋白质合成量下降等现象，进而抑制菌体生长。而GMB抑制金黄色葡萄球菌的作用机制是增加细胞壁的通透性、降低能量代谢相关酶的活性，干扰其正常的代谢活动。

关键词：姜厚朴；大肠杆菌；金黄色葡萄球菌；抑菌机理

文章篇号：1673-9078(2016)2-84-92 DOI: 10.13982/j.mfst.1673-9078.2016.2.014 Antibacterial Mechanism of Ginger Mix-fried Magnolia Bark Extract against Escherichia coli and Staphylococcus aureus

LI Ting, Y ANG Shu-ran, CHEN Min, SONG Li-ya, HE Cong-feng

(Science College of Beijing Technology and Business University, Beijing Key Laboratory of Plant Resources Research and Development, Chinese Cosmetics Collaborative Innovation Center, Beijing 100048, China) Abstract: To determine the antibacterial mechanism of ginger mix-fried magnolia bark (GMB) against Escherichia coli and Staphylococcus aureus, the morphological structure of the bacterial cells, enzyme activity in the ion channels of cell membrane, and energy mechanism after treatment with GMB were studied. The results showed that the minimum inhibitory concentrations (MICs) of GMB against E. coli and S. aureus were 6.25 and 12.5 mg/mL, respectively. The absorbance values for extracellular alkaline phosphatase (AKP) and β-galactosidase in E. coli increased 1.78-fold and 4.24-fold, respectively. Four hours after GMB treatment, the conductivity of the culture medium changed significantly, and membrane Na+K+-A TPase activity increased from 0.42 to 1.74 mg prot/mL, which was 1.7 times higher than that of the negative control. There were vesicular or irregular projections on the cell surface of S. aureus, and the sorbitol dehydrogenase (SDH) activity, total adenosine triphosphate (A TP) activity, and soluble protein content decreased by 40%, 23.4%, and 17.9%, respectively, whereas AKP enzymatic activity and conductivity increased. These results suggested that GMB increased E. coli cell permeability by disrupting the cell wall and damaging membrane structure, which resulted in an outflow of intracellular material and a decreased amount of synthesized proteins, thereby inhibiting bacterial growth. GMB appeared to inhibit S. aureus by enhancing the cell wall permeability, reducing the activity of enzymes related to energy metabolism, and interfering with the normal metabolic activities.

Key words: ginger mix-fried magnolia bark; Escherichia coli; Staphylococcus aureus; antibacterial mechanism

当前，细菌污染所引起的食源性疾病是影响人类公共健康和食品安全的最大因素之一，其中引起食源收稿日期：2015-05-11

基金项目：北京市优秀人才培养资助D项目（2012D005003000006）

作者简介：李婷（1991-），女，在读研究生，研究方向为天然植物抑菌剂 通讯作者：宋丽雅（1974-），女，博士，副教授，研究方向为微生物与酶工程 性疾病的主要病原菌有沙门菌、金黄色葡萄球菌和大肠杆菌[1]。细菌污染食品后分解食物中的蛋白质、糖、脂肪、维生素等营养物质，从而进行自身繁殖，最终导致食品的营养价值和品质下降，严重时造成食品腐败变质，呈现出一定的令人难以接受的感官性状，如刺激性气味、组织腐烂等。此外，有些细菌污染食品后会产生毒素，如肉毒毒素、金黄色葡萄球菌肠毒素

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