Antibacterial Activity and Mechanism of Linalool against Shigella sonnei and Its Application in Lettuce

Abstract

Shigella sonnei (S. sonnei) infection accounted for approximately 75% of annual outbreaks of shigellosis, with the vast majority of outbreaks due to the consumption of contaminated foods (e.g., fresh vegetables, potato salad, fish, beef, etc.). Thus, we investigated the antibacterial effect and mechanism of linalool on S. sonnei and evaluated the effect of linalool on the sensory quality of lettuce. The minimum inhibitory concentration (MIC) of linalool against S. sonnei ATCC 25931 was 1.5 mg/mL. S. sonnei was treated with linalool at 1× MIC for 30 min and the amount of bacteria was decreased below the detection limit (1 CFU/mL) in phosphate-buffered saline (PBS) and Luria-Bertani (LB) medium. The bacterial content of the lettuce surface was reduced by 4.33 log CFU/cm2 after soaking with linalool at 2× MIC. Treatment with linalool led to increased intracellular reactive oxygen species (ROS) levels, decreased intracellular adenosine-triphosphate (ATP) content, increased membrane lipid oxidation, damaged cell membrane integrity, and hyperpolarized cell membrane potential in S. sonnei. The application of linalool to lettuce had no effect on the color of lettuce compared to the control. The sensory evaluation results showed that linalool had an acceptable effect on the sensory quality of lettuce. These findings indicate that linalool played an antibacterial effect against S. sonnei and had potential as a natural antimicrobial for the inhibition of this foodborne pathogen.

Antibacterial effect of ultrasound and β-citronellol against Listeria monocytogenes and its application in carrot preservation

“…This may be a result of the action of ethylene oxide on the cellular tissues of the fruit, which may undergo structural changes that directly affect the firmness of the fruit. The results of Su et al [65] suggested that the addition of linalool may lead to a change in the pH of the soaking solution, which alters the changes in the texture of the lettuce leaves. Linalool may also react with damaged material in freshly cut leaves, leading to changes in sensory quality.…”

Studies on the Inhibition Mechanism of Linalyl Alcohol against the Spoilage Microorganism Brochothrix thermosphacta

“…In past studies, it has also been demonstrated that linalyl alcohol can exhibit excellent antimicrobial activity against a wide range of food-contaminating bacteria such as Shewanella putrefaciens, Pseudomonas aeruginosa, and Shigella [22][23][24]. But fewer studies have been conducted on how linalyl alcohol prevents B. thermosphacta.…”

“…However, earlier studies have suggested that it can harm cell membrane integrity, produce macromolecules and intracellular enzyme efflux, avert protein synthesis, and impede cellular metabolism [22,23]. Additionally, linalyl alcohol can increase the membrane lipid oxidation-induced hyperpolarized cell membrane potential, decrease intracellular adenosine triphosphate (ATP) levels, and increase intracellular reactive oxygen species (ROS) concentrations [23][24][25][26]. As a result, the current work attempts to improve the antibacterial mechanism of linalyl alcohol by testing its disruptive and inhibitory effects on DNA, intracellular chemicals, and Brochothrix thermosphacta as a research topic.…”