Antimicrobial activity of multipurpose essential oil blends

Abstract

Two types of multipurpose essential oil blends, blend 11 containing eleven different essential oils and blend 12 containing twelve, were tested against bacterial strains of Pseudomonas aeruginosa ATCC 9027, Serratia marcescens ATCC 13880 and Staphylococcus aureus ATCC 6538 and against the fungi, Candida albicans ATCC 10231, Aspergillus fumigatus ATCC 10894 and Fusarium solani ATCC 36031 to determine the spectrum of in vitro antimicrobial activity using aromatograms (paper disc diffusion assays). Microbial growth was decreased by multipurpose blend 11 and blend 12 in a similar manner. The saline control disc did not inhibit antimicrobial growth while the two blends exhibited significant zones of inhibition for all 3 bacteria and for the 3 fungi. The greatest antibacterial activity of blend 11 and blend 12 was exhibited with P. aeruginosa and S. marcescens followed by S. aureus . A high level of activity was associated with C. albicans and a lower level with F. solani followed by A. fumigatus . It is clearly evident from previous published studies that no single essential oil will effectively inhibit the growth of all of the organisms in our study. However, our results demonstrate that blend 11 and blend 12 have a broad range of inhibitory activity affecting all of the microorganisms tested.