Maisa Mansour

A stone sarcophagus (excavated in 1992) from Behbeet el-Hager, El-Gharbieh, Egyptwas selected for this study. Petrographic microscope (PM), Light microscope (LM), X- Ray Diffraction analysis (XRD), Scanning electron microscope (SEM), polymerase chain reaction (PCR), and ri-bosomal RNA (rRNA) were used to identify the stone composition and to measure the growth of the microorganisms and their effect on the stone composition. Polarizing, light and scanning electron microscopes were used to study the stone thin sections .The results achieved identified nine different fungal species belonging to Cladosporium cladosporioides, Paecilomycesvariotii and Curvularialunata. Moreover, Bacillus megaterium bacteria isolates were also determined. The deep penetration of the microorganisms through the stone and the resultant deterioration was investigated.Cladosporium cladosporioides colonies and hyphae penetrated through the pores and caused pitting of the stone structure causing deep pits to bar = 216.5 m. Elemental analysis of the deteriorated stone Sarcophagus by fungi and bacteria indicated the decrease in calcium and magnesium. Bacillus megaterium led to the loss of calcium (from 57.6 to 50.0%) and the buildup of nitrogen in the deteriorated stone. Experimental studies on biocide application on the stone Sarcophagus were also carried out using essential oils (Tea tree oil, Lavender oil, Rosemary oil and Origanum oil), plant extracts (Synadeniu mgrantti and Codieumvarigatum) and fungicide (Tecto (Thiabendazole) 50% SC and Option 40% (cymoxanil WDG) in different concentrations. The results of this study, indicated that Origanum oil in a concentration as low as 0.125% (v/v) successfully inhibited the fungal growth of the treated stone, while Synadeniumgrantti inhibited the growth at 4% wt/v and 100 ppm of Option 40%. The antimicrobials used, were in compliance with our case study and with the proposed preservation solutions. All treatments were esthetically acceptable for archaeological objects, for instances; being colorless, transparent and safe. Furthermore, they were fairly stable and did not encounter any colour change with the time of experiment