| Affiliation: | 1. Bioingénierie et Dynamique Microbienne aux Interfaces Alimentaires (BioDyMIA, EA n°3733), IUT Lyon 1 site de Bourg en Bresse – Technopole Alimentec, Université de Lyon, Université Claude Bernard, Lyon 1 - ISARA Lyon, rue Henri de Boissieu, Bourg en Bresse, France;2. Bioingénierie et Dynamique Microbienne aux Interfaces Alimentaires (BioDyMIA, EA n°3733), IUT Lyon 1 site de Bourg en Bresse – Technopole Alimentec, Université de Lyon, Université Claude Bernard, Lyon 1 - ISARA Lyon, rue Henri de Boissieu, Bourg en Bresse, France Ecole de Biotechnologie et Technologie Alimentaire, Institut Polytechnique de Hanoi, Hanoi, Vietnam;3. Ecole de Biotechnologie et Technologie Alimentaire, Institut Polytechnique de Hanoi, Hanoi, Vietnam |
| Abstract: | The antibacterial activity of a Cinnamomum cassia essential oil (EO) and of its main component trans-cinnamaldehyde (90% w/w) was examined against five Listeria monocytogenes strains. The minimal inhibitory concentrations (MICs) of C. cassia EO against the five L. monocytogenes strains were identical (250 µg ml−1), while the minimal bactericidal concentrations (MBCs) ranged between 800 and 1200 µg ml−1. In order to study if this EO and trans-cinnamaldehyde altered the five strains at the membrane level, fluorescence anisotropy of 1,6-diphenyl-1,3,5-hexatriene (DPH) was measured in presence of different concentrations (1/2MIC, MIC, 2MIC) of these antibacterial agents. A concentration-dependent increase of fluorescence anisotropy of DPH in their presence reflecting a rigidification of the membrane was observed for the five strains. This modification of the membrane fluidity was associated with a perturbation of the selective membrane permeability, as a perturbation of the gradient between intracellular and extracellular pH was also observed. |
