Method for the enzymatic degradation of polyethylene terephthalate

A process for enzymatic depolymerization of semi-crystalline polyethylene terephthalate (PET) comprising bringing said semi-crystalline PET into contact with an enzyme capable of depolymerizing said semi-crystalline PET, said enzyme selected from cutinases comprising an amino acid sequence having at least 75% identity with SEQ ID NO:1, and further comprising at least one mutation combination selected from:

• (i) F208I+D203C+S248C+Y92G, (ii) F208W+D203C+S248C+Y92G, or (iii) F208I+D203C+S248C+V170I+Y92G, corresponding to the residues of SEQ ID NO:1, wherein:
• a) the semi-crystalline PET has an initial degree of crystallinity of at most 25%;
• b) the depolymerization step is carried out at a temperature T equal to the Tg+10° C. of said semi-crystalline PET;
• and
• c) the enzyme has a depolymerization time (tD) of the semi-crystalline PET that is less than the crystallization time (tR) of said semi-crystalline PET, wherein the time tD represents the time required for said enzyme to depolymerize at least 80% of said semi-crystalline PET at said temperature T, and the time tR represents the time required for said semi-crystalline PET to reach a degree of crystallinity of at most 35% at said temperature T.