Enzymatic\nPreparation of Machine-Washable Antibacterial\nWool through a Subtraction-Addition Technique Using Hydrolase and\nTransglutaminase

Enzymatic antifelting finishing, as an eco-alternative\nfor conventional\nchlorination, has attracted increasing attention in wool processing.\nNevertheless, proteases are often subject to the disadvantage of significant\nfiber damage, which is mainly due to the hydrolysis of low-crystallinity\ncell membrane complexes rather than wool scales. Herein, a full enzymatic\nsubtraction-addition approach was applied to the antifelting finishing\nof wool textiles, that is, the enzymatic hydrolysis of the highly\ncross-linked wool scales was carried out by using the hydrolases of\nkeratinase and protease, and then, a glutamine-modified ε-poly-l-lysine (mPLL) was grafted to wool fibers under the catalysis\nof transglutaminase for enhancing the antifelting effect. According\nto the test standard of IWS-31, the shrinkage rate of the obtained\nwool fabric was reduced to 2.98%, and the strength loss was less than\n10%, accompanied with encouraging antibacterial activities against Staphylococcus aureus and Escherichia\ncoli, both reaching 100% of antibacterial rates after\ncontact with the bacteria. Meanwhile, low-temperature dyeing can be\nachieved by enzymatically reducing the density of wool scales, and\nthe mPLL network formed on the wool surface ensures a satisfactory\ncolorfastness to washing and rubbing up to level 4.5. The present\nenzymatic subtraction-addition technique provides a green route for\nthe functionalization of wool textiles.