Urethanases for the enzymatic degradation of polyurethanes

A method comprising utilizing a polypeptide for cleaving a urethane group, the polypeptide having an amino acid sequence selected from the group consisting of SEQ ID No. 3, SEQ ID No. 2, SEQ ID No. 4, SEQ ID No. 5, SEQ ID No. 6, SEQ ID No. 8, SEQ ID No. 10, SEQ ID No. 7, and variants of said polypeptides, characterized in that the polypeptide has urethanase activity in the enzymatic cleavage of urethane linkages, wherein variants is defined as an amino acid sequence having at least 90% sequence identity with a polypeptide to which it refers.