A team of researchers has developed an engineered PET depolymerase that efficiently breaks down and recycles plastic bottles. The enzyme, derived from a cutinase, achieves over 90% depolymerization of PET into monomers within 10 hours, with a productivity of 16.7 grams of terephthalate per liter per hour. This enzyme outperforms existing PET hydrolases, including those from the bacterium Ideonella sakaiensis. The study also demonstrates that biologically recycled PET with properties similar to petrochemical PET can be produced from enzymatically depolymerized waste, contributing to a circular economy. The enzyme, LCC, was optimized through site-directed mutagenesis and engineering of a disulfide bridge to enhance its thermostability. The optimized variants, such as ICCG and WCCG, showed improved activity and stability, achieving high conversion rates of post-consumer PET waste. These variants were tested in bioreactors under industrial conditions, achieving up to 85% conversion of PET waste in 15 hours. The enzyme's performance was validated using commercially available PET, showing high productivity and efficiency. The study highlights the potential of enzymatic processes for PET recycling, which could help address the global plastic waste problem. The developed enzyme could be used to produce recycled PET with properties comparable to virgin PET, supporting the concept of a circular economy. The research also emphasizes the importance of enzyme engineering in improving the efficiency and cost-effectiveness of biodegradation processes. The findings suggest that enzymatic processing of PET waste could play a significant role in achieving sustainability goals and reducing plastic pollution.A team of researchers has developed an engineered PET depolymerase that efficiently breaks down and recycles plastic bottles. The enzyme, derived from a cutinase, achieves over 90% depolymerization of PET into monomers within 10 hours, with a productivity of 16.7 grams of terephthalate per liter per hour. This enzyme outperforms existing PET hydrolases, including those from the bacterium Ideonella sakaiensis. The study also demonstrates that biologically recycled PET with properties similar to petrochemical PET can be produced from enzymatically depolymerized waste, contributing to a circular economy. The enzyme, LCC, was optimized through site-directed mutagenesis and engineering of a disulfide bridge to enhance its thermostability. The optimized variants, such as ICCG and WCCG, showed improved activity and stability, achieving high conversion rates of post-consumer PET waste. These variants were tested in bioreactors under industrial conditions, achieving up to 85% conversion of PET waste in 15 hours. The enzyme's performance was validated using commercially available PET, showing high productivity and efficiency. The study highlights the potential of enzymatic processes for PET recycling, which could help address the global plastic waste problem. The developed enzyme could be used to produce recycled PET with properties comparable to virgin PET, supporting the concept of a circular economy. The research also emphasizes the importance of enzyme engineering in improving the efficiency and cost-effectiveness of biodegradation processes. The findings suggest that enzymatic processing of PET waste could play a significant role in achieving sustainability goals and reducing plastic pollution.