Linalool Affects the Antimicrobial Efficacy of Essential Oils

The high concentrations of essential oils are generally required to receive microbial purity of the products (cosmetics, medicine). On the other hand, their application due to the high concentration of essential oils may be limited by changes in organoleptic and textural quality of the products, as well as they cause irritation and allergies in users. Addition of linalool to essential oil may significantly enhance its antimicrobial effectiveness and reduce their concentrations in products, taking advantage of their synergistic and additive effects. The aim of the study was to compare antimicrobial activity of essential oil alone and in combination with linalool. The antimicrobial activity of the essential oil of Thymus vulgaris, Juniperus communis, Pelargonium graveolens, Citrus bergamia, Citrus grandis, Lavandula angustifolia, Cinnamomum zeylanicum, Melaleuca alternifolia, Syzygium aromaticum, linalool and their combination was investigated against bacteria and fungi using the disc diffusion method. The addition of linalool to S. aromaticum oil in a synergistic manner enhanced its antimicrobial efficacy against P. aeruginosa and A. brasiliensis. Moreover, the additive interaction between this oil and linalool was observed against S. aureus, E. coli and C. albicans. It was also found that linalool in an additive manner increased the antimicrobial effectiveness of T. vulgaris oil against P. aeruginosa. The antimicrobial properties of mixture of essential oils with their active constituents may be used for creating new strategies to maintain microbiological purity of products.