Keratin waste is classified into three categories in regulation (EC) 1774/2002 of the European Parliament and Council of 3rd October 2002 laying down health rules concerning animal by-products which are not intended for human consumption but does not spread diseases to humans or animals (Korniłłowicz-Kowalska and Bohacz 2011). In the form of solid biomass, keratin is less prone to enzymatic hydrolysis due to high cross-linking by hydrogen bonding, disulfide bonds, and hydrophobic interactions