Induction of Fatty Acid Composition Modifications and Tolerance to Biocides in Salmonella enterica Serovar Typhimurium by Plant-Derived Terpenes

• Published in: Applied and Environmental Microbiology 2011-02, Vol.77 (3), p.906-910
• Main Authors: Dubois-Brissonnet, Florence, Naïtali, Murielle, Mafu, Akier Assanta, Briandet, Romain
• Format: Article
• Language: English
• Subjects: Adaptations; Agricultural sciences; Biological and medical sciences; Cell Membrane - chemistry; Cell Membrane - drug effects; Cells; Disinfectants - pharmacology; Drug Tolerance; Eugenol - chemistry; Eugenol - pharmacology; Fatty acids; Fatty Acids - analysis; Food Industry; Food Microbiology; Food Safety; Fundamental and applied biological sciences. Psychology; Humans; Hydrocarbons; Life Sciences; Membranes; Microbial Sensitivity Tests; Microbiology; Monoterpenes - chemistry; Monoterpenes - pharmacology; Peracetic Acid - pharmacology; Quaternary Ammonium Compounds - pharmacology; Salmonella; Salmonella enterica; Salmonella typhimurium - chemistry; Salmonella typhimurium - drug effects; Salmonella typhimurium - growth & development; Studies; Thymol - chemistry; Thymol - pharmacology
• ISSN: 0099-2240; 1098-5336; 1098-6596
• DOI: 10.1128/AEM.01480-10

To enhance food safety and stability, the food industry tends to use natural antimicrobials such as plant-derived compounds as an attractive alternative to chemical preservatives. Nonetheless, caution must be exercised in light of the potential for bacterial adaptation to these molecules, a phenomenon previously observed with other antimicrobials. The aim of this study was to characterize the adaptation of Salmonella enterica serovar Typhimurium to sublethal concentrations of four terpenes extracted from aromatic plants: thymol, carvacrol, citral, and eugenol, or combinations thereof. Bacterial adaptation in these conditions was demonstrated by changes in membrane fatty acid composition showing (i) limitation of the cyclization of unsaturated fatty acids to cyclopropane fatty acids when cells entered the stationary phase and (ii) bacterial membrane saturation. Furthermore, we demonstrated an increased cell resistance to the bactericidal activity of two biocides (peracetic acid and didecyl dimethyl ammonium bromide). The implications of membrane modifications in terms of hindering the penetration of antimicrobials through the bacterial membrane are discussed.