https://www.cas.cn/syky/202402/t20240227_5006277.shtml
https://doi.org/10.1038/s41467-024-45662-9
The research team of Wu Bian at the CAS Institute of Microbiology has redesigned a cutinase for nearly complete PET depolymerization at industrially relevant high-solids loading.
In recent years, enzymatic depolymerization for PET recycling has become the primary option for solving the PET plastic pollution crisis in the plastics circular economy. in 2020, a French team achieved 90% depolymerization and recycling of PET plastics on an industrial scale using a bio-enzymatic method. However, the high-temperature operating conditions resulted in the formation of non-degradable, highly crystalline waste from the residual 10% PET, hindering its application in real-world industrial scenarios and becoming a challenge in the plastics circular economy.
The CAS team used an artificial intelligence strategy to redesign PET hydrolases by intelligently shaping BhrPETase, a hydrolase from the bacterium HR29. The redesigned variant, TurboPETase, achieved complete depolymerization of PET waste with high substrate loadings within 8 h. The depolymerization efficiency exceeded that of the efficient PET depolymerization enzymes currently reported internationally, demonstrating the potential of TurboPETase in PET waste recycling. Kinetic and structural analyses suggest that the improved depolymerization performance may be attributed to a more flexible PET binding groove, highlighting the importance of improving polymer interactions at specific attack sites, and providing a new scenario to further promote the industrialization of other polyester-based biodegradation.