MICROATMOSPHER AND MICRODILUTION METHODS TO EVALUATE ANTIFUNGAL ACTIVITY OF SIX ESSENTIAL OILS ON ASPERGILLUS NIGER AND PENICILLIUM SP ISOLATED FROM THE UNIVERSITY OF YAOUNDE I LIBRARY

Kengne Gounmadje Landry*, Nyegue Maximillienne Ascension and Etoa François-Xavier

ABSTRACT

A. niger and Penicillium sp are the most frequent molds in libraries. Their presence can cause allergy-like reactions as well as infections in library users. They can also attack collections and library buildings due to their cellulolytic abilities. The aim of this study was to investigate the antifungal effect of six essential oils (EOs) against fungi isolated from a university library. This antifungal activity was assessed using broth dilution, and micro-atmosphere methods. Micro-atmosphere methods were carried out in terms of minimal inhibitory concentration, minimal fungicidal concentration (MIC, MFC in μl/mL of air) and percentage of mycelia growth inhibition of the tested fungus, while broth microdilution method was used to determined MIC and MFC in mg/mL. The whole EOs samples were found to be efficient in inhibiting the mycelia growth with complete inhibition on Penicillium sp and Aspergillus niger at the MIC value of 0.5 μL/mL of air. The MICs for radial mold growth ranged from 0.125 μL/mL to 1 μL/mL and CMFs from 0.125 μL/mL to 1.25 μL/mL. In broth microdilution method, MICs ranged from 0.19 to 6.25 mg/mL for the EOs and from 0.03 mg/mL for Nystatin ® on the two fungal isolates. Overall, the EO of Eugenia caryophylla showed better activity with a fungicidal effect on the fungi isolates tested. All of these results allow to conclude on a potential use of EOs in library disinfection.

Keywords: Essential oils, Antifungal activity, Micro atmosphere, Broth dilution.