Changes in Membrane Fatty Acids Composition of Microbial Cells Induced by Addiction of Thymol, Carvacrol, Limonene, Cinnamaldehyde, and Eugenol in the Growing Media

Abstract

Major active compounds from essential oils are well-known to possess antimicrobial activity against both pathogen and spoilage microorganisms. The aim of this work was to determine the alteration of the membrane fatty acid profile as an adaptive mechanism of the cells in the presence of a sublethal concentration of antimicrobial compound in response to a stress condition. Methanolic solutions of thymol, carvacrol, limonene, cinnamaldehyde, and eugenol were added into growth media of Escherichia coli O157:H7, Salmonella enterica serovar typhimurium, Pseudomonas fluorescens, Brochothrix thermosphacta, and Staphylococcus aureus strains. Fatty acid extraction and gas chromatographic analysis were performed to assess changes in membrane fatty acid composition. Substantial changes were observed on the long chain unsaturated fatty acids when the E. coli and Salmonella strains grew in the presence of limonene and cinnamaldehyde and carvacrol and eugenol, respectively. All compounds influenced the fatty acid profile of B. thermosphacta, while Pseudomonas and S. aureus strains did not show substantial changes in their fatty acid compositions.

Influences of cinnamic aldehydes on H+ extrusion activity and ultrastructure of Candida

“…Part of the effects caused by these cinnamic aldehydes come from alterations in the activity of dehydrogenases and depletion of NADPH. SEM and TEM analyses performed in this study, on a representative Candida strain ATCC 10261 cells treated with compounds for 14 h, clearly demonstrate the effects of cinnamic aldehydes on membrane-and cell-wall structure, as suggested by other investigators as an effect of cinnamaldehyde (Bang et al, 2000;Giordani et al, 2006;Xie et al, 2004;Di Pasqua et al, 2006, 2007 To conclude, cinnamaldehyde, coniferyl aldehyde and sinapaldehyde are found to be effective anticandidal agents against several fluconazole-sensitive and -resistant clinical isolates. The immediate effect of this antifungal activity may originate from the inhibition of PM-ATPase and decrease of pHi.…”

“…Cinnamaldehyde occurs naturally in the bark of cinnamon trees and other species of genus Cinnamomum, such as camphor and cassia. Cinnamaldehyde inhibits the growth of bacteria, yeast and filamentous moulds and is thought to act by inhibiting ATPases (Shreaz et al, 2010;Usta et al, 2003;Gill & Holley, 2004) and cell-wall biosynthesis (Bang et al, 2000) and by changing membrane structure and integrity (Giordani et al, 2006;Xie et al, 2004;Di Pasqua et al, 2006, 2007. Derivatives of cinnamaldehyde, such as 4-hydroxy-3-methoxycinnamaldehyde (coniferyl aldehyde) and 3,5-dimethoxy-4-hydroxycinnamaldehyde (sinapaldehyde), have also been shown to affect fungal growth and metabolism (Larsson et al, 2001;Larroy et al, 2002;Li et al, 2000).…”

Antimicrobial Activity ofSatureja HortensisL. Essential Oil Against Pathogenic Microbial Strains

“…the present results demonstrate high activity against wide spectrum of pathogenic Gram (-) and Gram (+) bacteria and three fungal strains. High antimicrobial activity is explained firstly by the fact that the fenol compound carvacrol (67.00%) is the main constituent of the oil, present in very high percentage (3,5,9,11,15,16,18,20). Most of the studies on the mechanism of this phenolic compound focused on its effects on cellular membranes, where the compound is altering the membrane function and in some instances its structure, causing swelling and an increase in its permeability.…”

Evaluation of the Antifungal Activities of Three Essential Oil Components Against Penicillium Expansum Spores

“…Thus, the destabilized membranes of the attacked microorganisms become permeable. What causes a loss of ions and thus induces a difference of potential at the membranaire level [38][39][40][41]. Always in the same vein, the lipids and proteins would be also affected [39; 42].…”