香茅醛对金黄色葡萄球菌的抑制作用

作者:Zhang Mao; Zhang Yehui; Li Hui; Xiao Xinglong; Yu Yigang*
来源:Modern Food Science and Technology, 2023, 39(1): 120-126.
DOI:10.13982/j.mfst.1673-9078.2023.1.0207

摘要

The minimal inhibitory concentration of Citronellal against Staphylococcus aureus was determined using broth dilution and the results were analyzed using a time-kill curve. Citronellal showed a rapid bactericidal effect at a minimum concentration of 0.80 mg/mL. After treating Staphylococcus aureus with 1.60 mg/mL of Citronellal for 0.5 h, the live bacteria count decreased from 5.65 log CFU/mL to 0.00 CFU/mL. After Citronellal treatment, the extracellular potassium ion concentration of Staphylococcus aureus increased significantly to 2.63 mg/L, and the fluorescence intensity of propidium iodide was 5 326.83 A.U. greater than that of the control group. This demonstrated that Citronellal can affect the permeability of Staphylococcus aureus cell membranes, causing leakage of intracellular micro- and macromolecules. Scanning electron microscopy results showed that high concentrations of Citronellal could seriously damage the morphology and structure of Staphylococcus aureus cells. UV-visible spectrum analysis showed that after adding Staphylococcus aureus DNA to Citronellal, the absorption peak exhibited a clear enhancement effect, with a maximum difference of 0.45 A.U. compared with the control group. This suggested that Citronellal interacts with DNA via groove binding, interfering with the normal biological function of DNA, and inhibiting cell growth. In conclusion, Citronellal could be used as a natural and efficient bacteriostatic agent preventing the growth of Staphylococcus aureus by destroying cell membrane integrity, altering DNA structure, and interfering with normal physiological activities of the bacterial cells. This study provides a theoretical basis for the application of Citronellal in the food industry. ? 2023 South China University of Technology.

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