食品科学 ›› 2012, Vol. 33 ›› Issue (17): 193-197.

• 生物工程 • 上一篇    下一篇

胡桃醌对大肠杆菌细胞膜作用研究

吴朝霞1,2,高 跃1,黄 姗1,张 琦1,徐亚平3   

  1. 1.沈阳农业大学食品学院 2.沈阳农业大学营养、质量与安全研究所 3.朝阳工程技术学校
  • 收稿日期:2011-07-05 修回日期:2012-07-10 出版日期:2012-09-15 发布日期:2012-11-09
  • 通讯作者: 吴朝霞 E-mail:wuzxsau@163.com
  • 基金资助:

    核桃青果皮中萘醌类化合物抑菌机理的研究

Effect of Juglone on the Cell Membrane of Escherichia coli

  • Received:2011-07-05 Revised:2012-07-10 Online:2012-09-15 Published:2012-11-09

摘要: 通过考察胡桃醌对大肠杆菌细胞膜的作用来研究胡桃醌的抑菌机理。采用3种不同质量浓度的胡桃醌作用于大肠杆菌后,测定培养液中的相对电导率、蛋白质质量浓度和细胞内外K+、Na+含量的变化,并结合透射电镜图来分析胡桃醌对大肠杆菌细胞膜的影响。结果表明:胡桃醌能够改变大肠杆菌细胞膜的渗透性,大量带电离子和蛋白质外漏;菌体细胞内外K+、Na+含量与空白对照组相比变化显著。透射电镜观察,经胡桃醌作用后菌体细胞被破坏,细胞膜变薄,细胞个体之间界限变模糊,内容物流出。并且,随胡桃醌质量浓度的增加和作用时间的延长,对大肠杆菌细胞膜的破坏越显著。显示胡桃醌的抑菌活性与其对大肠杆菌细胞膜的破坏有直接关系。

关键词: 胡桃醌, 大肠杆菌, 细胞膜, 作用

Abstract: Juglone (5-hydroxyl-1,4-naphthalene hydroquinone), a natural antibacterial compound, has reportedly showed  antibacterial effect on many microbial species. However, its antibacterial mechanism has never been reported. In this study, the effect of juglone on the cell membrane of Escherichia coli during culture in the presence of juglone at various concentrations was evaluated in terms of relative conductivity, protein content, K+ and Na+ efflux, and also examined under transmission electron microscopy (TEM). The results showed that juglone increased membrane permeability and therefore resulted in an outflow of charged ions and protein. Compared with the control samples, K+ and Na+ concentrations revealed a significant change. TEM observation exhibited that E. coli cells were destroyed by juglone, causing thin cell membrane, blurred cell boundary and outflowed cytoplasm. In addition, increasing juglone concentration could result in more obvious damage to the cell membrane in E. coli. In conclusion, the inhibitory activity of juglone is directly related to its damage to the cell membrane of E. coli.

Key words: juglone, Escherichia coli, cell membrane, effect

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