Influence of extraction methods and solvents on the antimicrobial activity of pickled Ferula orientalis

The aim of this study was to determine the antimicrobial effects of the essential oil and various extracts of pickled Ferula orientalis L. Two Gram (-) bacteria (Escherichia coli, Pseudomonas aeruginosa), two Gram (+) bacteria (Staphylococcus aureus, Streptococcus mutans), two yeast (Saccharomyces cerevisiae, Candida albicans), and two mold (Aspergillus niger, Penicillium roqueforti) strains were used to determine the antimicrobial effect of the extracts on different cell types. The extracts were prepared using classical and ultrasonic methods with five different solvents (water, ethanol: water, methanol: water, chloroform, and n-hexane). The essential oil was obtained by hydrodistillation. The in vitro antimicrobial assays showed that the essential oil and extracts were more effective on Gram (+) bacteria and molds. The highest antibacterial activity was exhibited against S. mutans with ultrasonic ethanol: water extract (31.25 mu g mL(-1)). In addition, the essential oil exhibited strong inhibitory activity against A. niger (MIC: 62.5 mu g mL(-1)) compared to the other tested microorganisms. The results showed that solvent diversity had an important effect on antimicrobial activity of all the tested microorganisms (p < 0.01) and the extraction method (classical or ultrasonic) was effective on E. coli, P. aeruginosa, C. albicans, A. niger, and P. roqueforti (p < 0.05).