Antimicrobial activity and chemical composition of Citrus aurantifolia (Christm.) Swingle essential oil from Italian organic crops

In this study, the essential oil of Citrus aurantifolia (Christm.) Swingle was extracted by hydrodistillation and, after chemical characterization, was evaluated for its antimicrobial activity on a representative range of ATCC and clinical strains. The chemical composition of the volatile fraction of key lime oil was determined using gas chromatography-mass spectrometry (GC-MS) and GC-flame ionization detection (GC-FID). The antimicrobial activity of the oil was evaluated on a representative range of Gram-positive bacteria, Gram-negative bacteria and yeasts, including ATCC and clinical strains, by the disc diffusion method and the broth microdilution method. The major components of lime essential oil proved to be beta-pinene (12.6%), limonene (53.8%), gamma-terpinene (16.5%), terpinolene (0.6%), alpha-terpineol (0.4%) and citral (2.5%), which are very likely responsible for the good antimicrobial activity, in particular on Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis and Staphylococcus epidermidis).