Antimicrobial activities of laboratory produced essential oil solutions against five selected fungal strains

Abstract

It is well known that essential oils possess significant antimicrobial activity. This study was conducted to estimate the antimicrobial activity of various types of Biokill, a laboratory produced solution composed of several essential oils (Biokill dissolved in 96% ethanol; Biokill 96% further dissolved in DMSO; Biokill dissolved in 70% ethanol and Biokill 70% further dissolved in DMSO). The antimicrobial activity was evaluated against five selected fungal strains, Candida albicans ATCC 10231, Saccharomyces cerevisiae ATCC 9763, Aspergillus niger I.N. 1110, Aspergillus sojae CCF and Penicillium spp. FNS FCC 266. A variation of the microtiter plate-based antimicrobial assay was used in order to assess the antimicrobial activity of the solutions. By applying this assay minimal inhibitory concentrations (MIC) of the Biokill solutions were determined for each strain of the selected test microorganisms. The results demonstrated that all variations of Biokill showed antimicrobial activity at concentrations lower than 2.5μg/mL. Biokill 70% further dissolved in DMSO showed the best antimicrobial properties against all the selected strains with MICs less than 1.25μg/mL. These results indicated that Biokill could find application in the pharmaceutical industry, in food preservation and conservation, in the prevention and treat­ment of plants infected by certain phytopathogens, etc.

Keywords

• Antimicrobial activity
• Essential oils
• Microtiter plate-based assay
• Minimal Inhibitory Concentration