الفهرس | Only 14 pages are availabe for public view |
Abstract Wood decay is important for ecosystem functioning and recycling of organic matter in the environment, but sometimes this natural process leads to destruction of wooden objects of historic and cultural value. Although wood persists for long periods of time, chemical, physical, and morphological modifications produced by unfavorable environmental conditions along with biodeterioration caused by microbial attack can result in loss of cultural heritage. Wood and other lignocellulosic materials are formed by polymeric constituents, cellulose, pectin, hemicellulose and lignin. Lignocellulosic materials are efficiently degraded by cellulolytic fungi, bacteria, actinomycetes and protozoa. However fungi are well known agents of decomposition of organic matter, in general, and of cellulosic substrate in particular. In this study a survey in different archaeological areas (Islamic ~rt Museum, Storage area of Cheops’s Solar Boat, Excavation of Saqqara and Grand Egyptian Museum) was made and many different microbial swabs and samples from different deteriorated wooden artifacts were obtained. These wooden artifacts had microbial infestation because of its organic origin and exposure to favourable environmental condition for microbial growth. In this study, one hundred and twelve fungal isolates were isolated from different wooden artifacts. Fifteen genera dominated the fungal isolates that were identified and these were Alternaria, Aspergillus, Chaetomium, Cladosporium, Emericella, Epicoccum, Eurotium, Paecilomyces, Pencillium, Phoma, Scopulariopsis, Stemphylium, Syncephalastrum, Trichophyton and Ulocladium. The genera of Aspergillus have occurrence with (48.210/0), followed by Pencillium (15.16%) and Cladosporium (l4.290/0).while other fungal species were detected at low incidence rate. Since wood degradation occurs by the actions of extracellular enzymes and other metaholites produced by fungus, the type and sequence of attack on wood cell wall components (i.e. cellulose, hemicelluloses and lignin) can vary depending on the specific degradative actions of the fungus. Pectinases are group of enzymes that weaken the plant cell wall and expose other polymers to degradation by hemicellulases and cellulases. In this study, Thirty seven fungal species have been screened for pectinases and cellulases [FPase and endoglucanase (CMCase )], ligninase production. Aspergillus amstelodarni and Aspergillus parasiticus were the best species for polygalacturonase production while Aspergillus brasiliensis and Penicillium duclauxii exhibited high cellulolytic activity among the other tested fungal isolates. Seven fungal species showed ligninolytic potential activity based on their ability to oxidize dyes. Fungi play a very important role in deterioration of ancient wood antiques and therefore the control of fungal growth must be studied carefully to avoid the loss of such value of these historical objects. In this study, control of icroorganisms by Ultaviolet (U.V.) light as physical control was investigated. It was revealed that slightly fungicidal effect of exposure 254 nm was determined In this study, it was carried out to investigate the antimicrobial activity of some medicinal plant extracts namely (Moringa peregrina seeds, Melia azedarach leaves, Azadirachta indica seeds, Azadirachta indica leaves, Olea europaea leaves and Tectona grandis leaves) against four against four fungal isolates Aspergillus brasiliensis, Penicillium duclauxii, Aspergillus amstelodami and Aspergillus parasiticus after the tested time periods. At 365nm, there was no fungicidal effect for tested time exposure for all fungal tested while there was increase in the growth fungal isolates Aspergillus brasiliensis, Penicillium duclauxii, Aspergillus amstelodami and Aspergillus parasiticus. Efficiency of each plant extract was tested by agar well diffusion method. With compared with antifungal drugs, It was shown that the crude extract not complete the inhibition of the growth. So this, present study directed to use chemical agent (DMSO). There was complete inhibition of the growth at concentration 50%. Also, 250/0 of DMSO inhibited growth by 60%. On the other hand low concentrations of DMSO were less effective. lnvivo studies, treatment the biodeteriorated sycamore wood with DMSO inhibited the fungal growth. Also, the application of DMSO had no effect on the colour, structure and chemical characteristic of the wood. |