Title : Innovative conservation method of egyptian historical textiles by using covalently Immobilized enzymes on nanoparticles
Abstract:
Historic textiles in museums and also in the burial environment are exposed to many different manifestations of damage, which may cause damage and loss of rare textile pieces. One of the most important manifestations of damage is dirt and stains, which are abundant on historical textiles. These stains and dirt cause physical deformation of the surface of historical textiles, damage and chemical decomposition, change in pH, attraction to insects and fungi, and also be a catalyst for irreversible damage. Traditional methods of getting rid of stains and dirt are sometimes ineffective and harmful to historical textiles. This study presents the use of a new effective and safe method by using bio-cleaning process (using pure enzymes) to get rid of stains in historical textiles. An experimental study prepared in the laboratory to study the efficiency, degree of safety, and application conditions of the new method. Because of the high price of commercial carriers that are used in enzyme immobilization, there is a persistent need to find cheap ones. Alginate and carrageenan are two polymers that are found naturally and are also cheap. Moreover, they can be used in many industries, such as food, pharmacy, textiles, and nutrition. Hence, the interaction between alginate and carrageenan polymers can improve the stability and activity of newly formed gel beads. Aiming at their biotechnological and industrial applications, amylase and lipase should be stable enough and can be used several times, reducing the final product cost. This can be done by immobilization technologies that improve stability and catalytic properties, leading to higher catalyst efficiency. Covalent immobilization has a great advantage in that it prevents enzyme leakage because of the strong bond that forms between the support and enzyme. So that immobilization via covalent bond is widely preferred in industry as it reduces product cost by using immobilized enzyme many times. Alginate/carrageenan complexes were used for covalent immobilization of α-amylase and lipase and in the cleaning and restoration of historical textiles. Lipase and α-amylase were immobilized on nanoparticles of the alginate/-carrageenan complex and used in historical textile cleaning. The preparation of nanoparticles, activation, and enzyme immobilization were characterized. Optimization of loading times and units of the two enzymes was done. It was found that the optimum time and units of immobilized amylase enzyme were 4 hours and 25 U, respectively. While the optimum time and units of immobilized lipase enzyme were 3 hours and 15 U, respectively, this method does not cause any staining or colour damage to the antique cloak. This method preserves the tissue from continuous disintegration. Close examination by using FT-IR, SEM, and TGA instrument.... Etc. was done in order to study and evaluate of nanoparticle preparation, activation, and enzyme immobilization. Finally, the treatment was applied to a historical scarf (dating back to 750 years ago), the scarf is made of cotton, and there is an opening in the front along the scarf. The historical scarf is located in a private room attached to Al-Sayyid Al-Badawi Mosque in Tanta, Egypt.
