Preparation of Antimicrobial Silk Yarn Using Protease and Nanosilver

Today, the use of enzymes and antibacterial protein fibers is greatly favored by researchers to protect textile against microbial attacks, spots, discoloration and to increase shelf life of silk carpets in museums. This study investigates the effect of protease and nanosilver on silk yarn. Silk yarn with 140 Tex as a carpet pile treated with protease and nanosilver in different conditions and their antimicrobial properties against two bacteria, i.e. Escherichia coli and Staphylococcus aureus was studied and compared. Also, some characteristics of products including weight loss, whiteness index and color indices, have been investigated in SEM images. Using nanosilver alone showed excellent antimicrobial properties against microbes with different concentrations while reduced the whiteness of silk yarn. However, using 2% protease led to enhanced antibacterial properties, and whiteness. On these bases, concurrent use of protease and 30 ppm of nanosilver produced silk yarn with excellent antibacterial properties i.e. 100% bacterial reduction.