Maisa Mansour

Citation:

NOSHYUTTA, W., E. OSMAN, and M. MANSOUR, "AN INVESTIGATION OF THE BIOLOGICAL FUNGICIDAL ACTIVITY OF SOME ESSENTIAL OILS USED AS PRESERVATIVES FOR A 19TH CENTURY EGYPTIAN COPTIC CELLULOSIC MANUSCRIPT", INTERNATIONAL JOURNAL OF CONSERVATION SCIENCE , vol. 7, issue 1, pp. 41-56 , 2016.

Abstract:

The main goal of this work was to investigate the biological fungicidal activity of some commercial essential oils of tea tree, lavender and thyme, which were to be applied as alternative preservatives for ancient manuscripts. To achieve our goal, model samples of cellulosic paper were made to mimic the original manuscript, which was a Coptic manuscript known as Pascha (the sacred week), dated 1812. Twenty-three microorganism strains were isolated representing twelve fungal taxa and one bacterial taxa which were identified in all collected and analyzed in samples, which included Trichoderma viride, Penicillium roqueforti, Eurotium chevalieri, Aspergillus flavus and Bacillus subtilis. A scanning electron microscope (SEM) was used to investigate the growth of the associated microorganisms and their effect on the sample paper structure. Different concentrations of the aforementioned essential oils were applied on the mimic samples, which were then subjected to accelerated ageing corresponding to 25 or 50 years of a natural one. To characterize the applied oils on the samples, we made records by using FTIR-ATR, color measurements according to CIELAB system, and analyzed the mechanical properties of the tested samples. The results revealed that the samples treated with either tea tree oil or lavender oil, had ΔE values that decreased as the oil concentration increased. However, when samples were treated with thyme oil the reverse was obtained. For the treated samples exposed to 25 years of light ageing, we noticed that the higher obtained tensile strength and % elongation of treated samples followed the ranking order: thyme > lavender > tea tree oils. For the treated samples that were exposed to 50 years of natural light ageing, we observed that almost all tensile strength and elongation values of the treated samples were higher than that of the untreated ones. Moreover, we noticed that the inhibition of growth of the microorganisms was obtained at a low concentration of tea tree oil (0.25% v/v). This treatment was esthetically acceptable for archaeological objects, because it was colorless, transparent and safe. Based on the results we obtained, the optimized essential oil, which is the oil with an appropriate concentration, was selected to be added to the cellulosic pulp used for the leaf casting. Moreover, the same optimized essential oil was applied on the paper samples to be used as separators between the ancient manuscript pages. After dismantling, cleaning, leaf casting and rebinding of the damaged parts, the manuscript is then preserved.