Effect of sealing and Tween 80 on the antifungal susceptibility testing ofessential oils

Concentrations of essential oils showing high volatility decreased substant ially in broth and agar media when incubated under open conditions. The dec rease in the half life was from 0.7 to 38 hr in broth medium at 27 C, When evaporation was prevented by sealing, MIC values against Aspergillus fumiga tus, Candida albicans and Trichophyton mentagrophytes by broth or agar dilu tion assay were lowered two to eight-fold, as compared with those obtained under open conditions. Addition of Tween 80 caused a rise of the MICs again st A. fumigatus by two to four-fold in broth dilution assay, but little aff ected the MICs in agar dilution assay.