<abstract xmlns="http://www.w3.org/1999/xhtml">

<p>Natural products such as essential oils (EOs) are secondary metabolites that can be obtained from either plant or animal sources or produced by microorganisms. Much attention has been given to exploring the use of secondary metabolites as natural antibacterial agents. This study investigates the antibacterial activity and mechanism of β-caryophyllene, a compound that can be found in various EOs, against <italic>Bacillus cereus</italic>. The minimum inhibitory concentration of β-caryophyllene against <italic>B. cereus</italic> was 2.5% (v/v), whereas killing kinetics of β-caryophyllene at minimum inhibitory concentration recorded complete bactericidal activity within 2 hours. Zeta-potential measurement in the cells treated with half the minimum inhibitory concentration of β-caryophyllene at 1.25% (v/v) showed an increase in the membrane permeability surface charge to –3.98 mV, compared to untreated cells (–5.46 mV). Intracellular contents leakage of UV-absorbing materials was detected in the cells treated with β-caryophyllene. Additionally, β-caryophyllene does not interfere with the efflux activity of <italic>B. cereus</italic> via the ethidium bromide influx/efflux activity. The results revealed that β-caryophyllene was able to alter membrane permeability and integrity of <italic>B. cereus</italic>, leading to membrane damage and intracellular content leakage, which eventually caused cell death.</p>
</abstract>

Natural products such as essential oils (EOs) are secondary metabolites that can be obtained from either plant or animal sources or produced by microorganisms. Much attention has been given to exploring the use of secondary metabolites as natural antibacterial agents. This study investigates the antibacterial activity and mechanism of β-caryophyllene, a compound that can be found in various EOs, against Bacillus cereus. The minimum inhibitory concentration of β-caryophyllene against B. cereus was 2.5% (v/v), whereas killing kinetics of β-caryophyllene at minimum inhibitory concentration recorded complete bactericidal activity within 2 hours. Zeta-potential measurement in the cells treated with half the minimum inhibitory concentration of β-caryophyllene at 1.25% (v/v) showed an increase in the membrane permeability surface charge to –3.98 mV, compared to untreated cells (–5.46 mV). Intracellular contents leakage of UV-absorbing materials was detected in the cells treated with β-caryophyllene. Additionally, β-caryophyllene does not interfere with the efflux activity of B. cereus via the ethidium bromide influx/efflux activity. The results revealed that β-caryophyllene was able to alter membrane permeability and integrity of B. cereus, leading to membrane damage and intracellular content leakage, which eventually caused cell death.

Antibacterial Activity and Mode of Action of β-caryophyllene on <italic>Bacillus cereus</italic>


Polish Journal of Microbiology

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Antibacterial Activity and Mode of Action of β-caryophyllene on 


Natural products such as essential oils (EOs) are secondary metabolites that can be obtained from either plant or animal sources or produced by microorganisms....

Antibacterial Activity and Mode of Action of β-caryophyllene on Bacillus cereus

Article Category: original-paper

Published Online: Mar 12, 2020

Page range: 49 - 54

Received: Oct 19, 2019

Accepted: Jan 18, 2020

DOI: https://doi.org/10.33073/pjm-2020-007

Keywords
antibacterial, β-caryophyllene, intracellular leakage, membrane damage, zeta potential

© 2020 Chew-Li Moo et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

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Antibacterial Activity and Mode of Action of β-caryophyllene on Bacillus cereus

Article Category: original-paper

Published Online: Mar 12, 2020

Page range: 49 - 54

Received: Oct 19, 2019

Accepted: Jan 18, 2020

DOI: https://doi.org/10.33073/pjm-2020-007

Keywordsantibacterial, β-caryophyllene, intracellular leakage, membrane damage, zeta potential

© 2020 Chew-Li Moo et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Fig. 1.

Fig. 2.

Fig. 3.

Keywords
antibacterial, β-caryophyllene, intracellular leakage, membrane damage, zeta potential