芳樟醇对大肠杆菌的抑菌作用机制

Antibacterial Mechanism of Linalool against Escherichia coli

摘要:

源于天然植物中的芳樟醇具有抗菌作用，但其对食源性致病细菌的作用机制还不清楚。通过研究芳樟醇处理后大肠杆菌的形态、细胞内容物和ATP的变化，初步探究芳樟醇对大肠杆菌的抑菌机制，结果表明：芳樟醇对大肠杆菌有较好的抗菌活性，生长曲线结果显示1×MIC、2×MIC大肠杆菌生长完全受到抑制。细胞形态观察结果表明，膜电位下降近85%，胞内蛋白相较最初泄露达到238.64 μg/mL，核酸相较最初泄露近81%，ATP含量下降至18.46 μmoL/L，表明该抑制作用首先是从细胞膜开始的，芳樟醇的疏水作用使其聚集在细胞膜上，影响细胞膜的结构和功能，使细胞膜通透性增大，细胞内容物丢失，ATP含量下降，细胞功能异常，导致细胞死亡。芳樟醇具有显著抑菌效果，有望开发出一种新型天然抗菌剂。

Abstract:

Linalool is derived from natural plants and has an antibacterial effects, although its mechanism of action against food-borne pathogenic bacteria remains unclear. The antibacterial mechanism of linalool against Escherichia coli was studied through examining the changes in morphology, cell contents and ATP of E. coli induced by the linalool treatment. The results showed that linalool exhibited good antibacterial activity against E. coli, and according to the growth curve, the growth of E. coli at 1×MIC and 2×MIC was completely inhibited. The results of cell morphology observations showed that the membrane potential decreased by almost 85%, with the intracellular protein leaked up to 238.64 μg/mL, the nucleic acid leaked almost 81%, and the ATP content decreasing to 18.46 μmoL/L. These results indicated that the inhibition started from the cell membrane. The hydrophobic effect of linalool enabled it to aggregate on the cell membrane, thereby affecting the structure and function of the cell membrane: increasing the permeability of the cell membrane, losing cell content, decreasing ATP content, causing cell dysfunction and cell death. Linalool has a remarkable antibacterial effect, and a new natural antibacterial agent is expected.