Chemical composition and antimicrobial activity of nine essential oils obtained by steam distillation of plants from the Souss-Massa Region (Morocco)

The antimicrobial properties of nine essential oils (EOs) from Souss-Massa, Morocco, were assessed and compared. The studied plants were: Mentha piperita, Mentha pulegium, Mentha spicata, Pelargonium graveolens, Rosmarinus officinalis, Thymus leptobotrys, Thymus pallidus, Thymus satureioides and Citrus limon. EOs were extracted by steam distillation and their minimum inhibitory concentrations (MICs) were determined versus ten bacteria strains (Enterobacter cloacae, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella Typhimurium, Listeria monocytogenes, Staphylococcus aureus (MRSA), Enterococcus faecalis, Streptococcus equinus and Streptococcus pyogenes), two yeasts (Candida albicans and Candida glabrata) and two fungi (Aspergillus niger and Penicillium funiculosum). Thymus leptobotrys, P.graveolens and T.satureioides showed interesting antimicrobial properties (MIC = [0.7-5.9 mu g/mL]). Mentha piperita, T.pallidus and M.spicata gave intermediary results (MIC= [5.7-23.2 mu g/mL]) while the remaining EOs displayed poor results (MIC= [23.2-85.5 mu g/mL]). EOs that contained primarily, in this order, phenolic terpenes, terpenic alcohols and terpenic aldehydes displayed better antimicrobial properties.