Effects of sub-lethal concentrations of thyme and oregano essential oils, carvacrol, thymol, citral and trans-2-hexenal on membrane fatty acid composition and volatile molecule profile of Listeria monocytogenes, Escherichia coli and Salmonella enteritidis

• Published in: Food chemistry 2015-09, Vol.182, p.185-192
• Main Authors: Siroli, Lorenzo, Patrignani, Francesca, Gardini, Fausto, Lanciotti, Rosalba
• Format: Article
• Language: English
• Subjects: Aldehydes - pharmacology; Anti-Infective Agents - isolation & purification; Anti-Infective Agents - pharmacology; Cell Membrane - drug effects; Cell Membrane - metabolism; Dose-Response Relationship, Drug; Escherichia coli - drug effects; Escherichia coli - growth & development; Escherichia coli - metabolism; Essential oils; Fatty Acids - metabolism; Listeria monocytogenes - drug effects; Listeria monocytogenes - growth & development; Listeria monocytogenes - metabolism; Membrane fatty acids; Monoterpenes - pharmacology; Natural antimicrobials; Oils, Volatile - isolation & purification; Oils, Volatile - pharmacology; Origanum - chemistry; Pathogens; Plant Oils - isolation & purification; Plant Oils - pharmacology; Principal Component Analysis; Salmonella enteritidis - drug effects; Salmonella enteritidis - growth & development; Salmonella enteritidis - metabolism; Thymol - pharmacology; Thymus Plant - chemistry; Volatile molecule profile
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2015.02.136

•Natural antimicrobials induced marked changes in pathogen membrane fatty acid profiles.•Natural antimicrobials induced marked changes in pathogen volatile molecule profiles.•The data contributed to the comprehension of the pathogen stress response mechanisms. The aim of this work was to investigate the modifications of cell membrane fatty acid composition and volatile molecule profiles of Listeria monocytogenes, Salmonella enteritidis, Escherichia coli, during growth in the presence of different sub-lethal concentrations of thyme and oregano essential oils as well as carvacrol, thymol, trans-2-hexenal and citral. The results evidenced that the tested molecules induced noticeable modifications of membrane fatty acid profiles and volatile compounds produced during the growth. Although specific differences in relation to the species considered were identified, the tested compounds induced a marked increase of some membrane associated fatty acids, particularly unsaturated fatty acids, trans-isomers, and specific released free fatty acids. These findings can contribute to the comprehension of the stress response mechanisms used by different pathogenic microorganisms often involved in food-borne diseases in relation to the exposure to sub-lethal concentrations of natural antimicrobials.