Antibacterial Activity and Mechanism of Ginger Essential Oil against Escherichia coli and Staphylococcus aureus

Abstract

Though essential oils exhibit antibacterial activity against food pathogens, their underlying mechanism is understudied. We extracted ginger essential oil (GEO) using supercritical CO2 and steam distillation. A chemical composition comparison by GC-MS showed that the main components of the extracted GEOs were zingiberene and α-curcumene. Their antibacterial activity and associated mechanism against Staphylococcus aureus and Escherichia coli were investigated. The diameter of inhibition zone (DIZ) of GEO against S. aureus was 17.1 mm, with a minimum inhibition concentration (MIC) of 1.0 mg/mL, and minimum bactericide concentration (MBC) of 2.0 mg/mL. For E. coli, the DIZ was 12.3 mm with MIC and MBC values of 2.0 mg/mL and 4.0 mg/mL, respectively. The SDS-PAGE analysis revealed that some of the electrophoretic bacterial cell proteins bands disappeared with the increase in GEO concentration. Consequently, the nucleic acids content of bacterial suspension was raised significantly and the metabolic activity of bacteria was markedly decreased. GEO could thus inhibit the expression of some genes linked to bacterial energy metabolism, tricarboxylic acid cycle, cell membrane-related proteins, and DNA metabolism. Our findings speculate the bactericidal effects of GEO primarily through disruption of the bacterial cell membrane indicating its suitability in food perseveration.

Preparation and Characterization of Bio-Nanocomposites Film of Chitosan and Montmorillonite Incorporated with Ginger Essential Oil and Its Application in Chilled Beef Preservation

“…In the previous study, we reported the antibacterial activity and mechanism of GEO against E. coli and Staphylococcus aureus [18]. In present research, the polysaccharide chitosan as the polymer matrix was combined with nano-clay montmorillonite and natural active substance GEO to prepare GEO, chitosan, and montmorillonite novel bionanocomposite films.…”

Membrane Disruption Properties of Essential Oils—A Double-Edged Sword?

“…The decrease in membrane potential may be attributed to the structural damage of the cell membrane [23]. Measuring the bacterial membrane potential can be achieved by determining the ratio between fluorescence dye intensities inside and outside the cell [23,24]. The membrane potential-sensitive dye, 3,3 -dipropylthiacarbocyanide iodide (DiSC35) [25][26][27] and bis-oxonol [9] are commonly used to stain the depolarised bacterial cells after exposure to EOs.…”

The Chemical Composition and Biological Activities of Essential Oils from Zanthoxylum rhetsa Grown in Son La, Northwest Vietnam

“…Pham et al suggested that terpinen-4-ol that is the main active constituent in Z. rhetsa pericarp EOs had the ability to inhibit stomach and intestine diseases [11]. Some other studies have also shown that essential oils obtained from plants exhibited potential antibacterial and antifungal activities [20][21][22].…”