Unfortunately, monuments all over the world may become discolored and degraded as a result of the growth and activity of fungi. Biodeterioration is an irreversible damage that is caused by microbial colonization on the surface of buildings. Different fungi were isolated from limestone False-door in Kom Aushim museum- El-Fayoum governorate, Egypt. These include; Aspergillus niger, A. fumigatus, A. sulphureus, A. flavus, Alternaria alternata, Alternaria spp., and Cladosporium herbarium. Fungal grow on modern limestone surfaces after 60 days of infection. Transmission electron microscope demonstrated the penetration and presence of fungal threads inside limestone. Environmental Scanning electron microscope attached with EDX Unit revealed an increase in carbon and magnesium ions from 9.16 to 12.17% and 1.41–1.51%, respectively after fungal infection of limestone, while other ions decreased after infection; aluminum from 1.96 to 1.39%, silicon from 7.40 to 3.57%, potassium from 0.44 to 0.41%, calcium from 41.41 to 35.04 % and iron from 1.08 to 0.90 %. p-Chloro-m-crysol is the most potent to inhibit the growth of isolated fungi at MIC 50 ppm for most fungal species.
