Antifungal activity of some plant extracts and essential oils against fungi-infested organic archaeological artefacts

The determination of the antifungal activities of nine kinds of powdered plant extracts and five essential oils was studied in vitro against four of the most common fungal species (Aspergillus flavus, A. versicolor, Penicillium sp. and P. purpurogenum), which were isolated from different organic materials from archaeological artefacts such as papyrus and linen. The essential oils showed greater efficacy than the powdered plant extracts, where thyme and lemongrass oils were the most potent. Also, the minimum inhibitory concentration and minimum fungicidal concentration of these oils were determined. Furthermore, their chemical components were identified using gas chromatography-mass spectrometry (GC-MS) analysis. In vivo, studies were performed using biodeteriorated samples for applying treatment, in which the microbiological test revealed that both oils can eradicate both tested fungi completely after exposure time, ranging from two weeks for papyrus samples to 14 weeks for linen. A scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR) and colorimeter were used to assess the treatment process, leading to the final results, which suggest that the essential oils could be useful sources of fungicidal preparations for the disinfection of biodeteriorated linen and papyrus artefacts. Nevertheless, further studies are strongly recommended to introduce these sources into practical use in preventive conservation.