School of Biological and Environmental Engineering, Chaohu University, Bantang Road No. 1, Chaohu Economic Development Zone, Hefei 238024, China.
J Food Prot. 2024 Oct;87(10):100345. doi: 10.1016/j.jfp.2024.100345. Epub 2024 Aug 13.
The objective of this study was to reveal the antibacterial mode of action of garviecin LG34 against S. aureus CICC 21600 and L. monocytogenes CICC 21633 and measure the inhibitions on these two foodborne pathogenic bacteria in milk. Antibacterial mechanism of garviecin LG34 was ascertained by its effect on the efflux of Potassium (K) ions, extracellular electrical conductivity, UV-absorbing substances, potential across the membrane (ΔΨ), and cell permeability. The inhibition of garviecin LG34 against S. aureus CICC 21600 and L. monocytogenes CICC 21600 in milk was studied by viable counting method. Supplementation with 160 AU/ml of garviecin LG34 had a bactericidal effect on S. aureus CICC 21600 and L. monocytogenes CICC 21633. A total of 80, 160, and 320 AU/ml of garviecin LG34 resulted in the effusion of potassium ion and UV-absorbing substances, the leakage of cellular electrolytes, and the dissipation of electrical potential across the membrane of these two food-borne bacteria and showed a dose-dependent. Moreover, the increase in cell permeability of both strains was observed by flow cytometer after cells treated with 160 AU/ml of garviecin LG34. Garviecin LG34 significantly inhibited the growth of these two food-borne bacteria in milk, especially in skimmed milk. Garviecin LG34 could cause pore formation, intracellular materials release, and permeability increase of S. aureus CICC 21600 and L. monocytogenes CICC 21633, and could be applied to milk as bio-preservative.
本研究旨在揭示 Garviecin LG34 对金黄色葡萄球菌 CICC 21600 和单核细胞增生李斯特菌 CICC 21633 的抑菌作用方式，并测定其在牛奶中的抑菌效果。通过测定钾离子（K）外流、胞外电导率、紫外吸收物质、膜电位（ΔΨ）和细胞通透性的变化，确定 Garviecin LG34 的抑菌机制。采用活菌计数法研究 Garviecin LG34 对牛奶中金黄色葡萄球菌 CICC 21600 和单核细胞增生李斯特菌 CICC 21633 的抑制作用。结果表明，160 AU/ml 的 Garviecin LG34 对金黄色葡萄球菌 CICC 21600 和单核细胞增生李斯特菌 CICC 21633 具有杀菌作用。80、160 和 320 AU/ml 的 Garviecin LG34 可引起两种食源性致病菌钾离子和紫外吸收物质的外渗、细胞电解质的渗漏以及膜电位的耗散，呈剂量依赖性。此外，用 160 AU/ml 的 Garviecin LG34 处理细胞后，通过流式细胞仪观察到两种菌株的细胞通透性均增加。Garviecin LG34 能显著抑制两种食源性致病菌在牛奶中的生长，尤其在脱脂乳中效果显著。Garviecin LG34 可导致金黄色葡萄球菌 CICC 21600 和单核细胞增生李斯特菌 CICC 21633 形成孔道、细胞内物质释放和通透性增加，可作为生物防腐剂应用于牛奶中。
