[Enhancing PET degradation efficiency through fusing carbohydrate-binding modules in LCC-ICCG].

Area of Science:

• Biotechnology
• Polymer Science
• Environmental Science

Context:

• Polyethylene terephthalate (PET) is a widely used polymer with significant environmental persistence.
• Enzymatic degradation of PET is a key area of research for sustainable plastic waste management.
• Carbohydrate binding modules (CBMs) can enhance enzyme-substrate interactions for improved degradation.

Purpose:

• To engineer a more efficient PET-degrading enzyme by introducing CBMs from various families into the LCC-ICCG enzyme.
• To evaluate the impact of different CBM types (A, B, and C) on the degradation of high-crystallinity PET powder and amorphous PET film.
• To identify the optimal CBM fusion for enhanced PET hydrolysis and thermal stability.

Summary:

• Fusion of type A and type C CBMs to LCC-ICCG significantly improved the degradation rate of amorphous PET film.
• The LCC-ICCG-CBM9-2 variant exhibited over a 10-fold increase in PET degradation rate compared to the original enzyme.
• Type B CBM fusion, conversely, reduced the enzyme's degradation efficiency and thermal stability (Tm) towards PET.

Impact:

• This study demonstrates a viable strategy to enhance enzymatic PET degradation through targeted CBM engineering.
• The developed fusion enzymes offer improved activity and thermal stability, advancing plastic degradation technologies.
• Findings contribute to developing effective solutions for plastic pollution and promoting environmental conservation.