This study investigated the antibacterial activity and mechanism of thymol against Pseudomonas fluorescens, focusing on its effects on membrane integrity, reactive oxygen species (ROS), membrane potential, permeability, and intracellular components (protein, K+, DNA).Thymol exhibited a minimum inhibitory concentration (MIC) of 125 mg/L and a minimum bactericidal concentration of 1 500 mg/L.At 1MIC and 2MIC, thymol reduced DiSC3(5) intensity by 40% and 80% respectively, indicating severe membrane depolarization.Meanwhile, the K+ concentration in bacterial suspension increased to 0.029 7 mmol/L and 0.041 7 mmol/L, while the protein concentration rose to 8.676 μg/mL and 117.044 μg/mL respectively, SDS-PAGE analysis revealed suppressed protein expression.Fluorescence microscopy demonstrated a decrease fluorescence in 4′,6-diamidino-2-phenylindole and the enhanced in propidium iodide. 2′,7′-dichlorofluoresein di-acetate assays showed significant ROS accumulation (P<0.05), and scanning electron microscopy validated the occurrence of membrane rupture.These results demonstrate that thymol disrupts membrane structure, induces oxidative stress via ROS overproduction, and inhibits DNA synthesis, leading to bacterial cell death.This study provides a theoretical foundation for thymol as a natural antibacterial agent in fish preservation.
CHEN Jiasi
,
LIU Xiaoli
,
WU Kegang
,
DUAN Xuejuan
,
YU Hongpeng
,
XU Jiawei
,
WU Leping
,
GUO Junxian
. Inhibition mechanism of thymol against Pseudomonas fluorescens[J]. Food and Fermentation Industries, 2026
, 52(3)
: 250
-255
.
DOI: 10.13995/j.cnki.11-1802/ts.042750
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