Recycling the recyclers: strategies for the immobilisation of a PET-degrading cutinase

Researchers at Friedrich-Alexander-Universität Erlangen-Nürnberg developed and tested methods to improve the stability and recyclability of a PET-degrading enzyme for plastic recycling. Using the INFORS HT Labfors bioreactor, the team compared several immobilization strategies and found that pH-responsive polymers delivered the best results, retaining about 80% of enzyme activity and enabling up to five PET degradation cycles. In batch reactions, the process achieved more than 97% terephthalic acid yield in less than 14 hours for the first three cycles and about 78% yield in the fifth cycle. These findings support more efficient and scalable processes for enzymatic PET recycling.