Simultaneous lice eggshell removal from wool and anti-felting with a single protease treatment

The residue of wool lice eggshells and felting are both important factors that affect the quality of wool. Since the main components of the eggshell cement and the wool scales are proteins, it is possible to remove the eggshells and decrease felting at the same time by protease treatment. In this work, AtP, a fungal protease from Aspergillus tubingensis, was discovered to be suitable for simultaneous eggshell removal and anti-felting. By optimizing the process, AtP can remove 88% of the eggshells and reduce the feltability by 29.4%, with only 6.3% reduction in the tensile strength of the wool. Mechanistic studies show that AtP is sensitive to the flatness of substrate surface and the density of disulfide bonds, which endows its relative selectivity between eggshell cement and wool. To our knowledge, this work reports the first ecofriendly technique to complete eggshell removal and anti-felting in one step, which will be not only beneficial for the wool industry, but can also be extended to similar use for pet or human hair.