Regulation of terephthalic acid metabolism drives the enhancement of PET degradation in Ideonella sakaiensis

The escalating crisis of polyethylene terephthalate (PET) waste has prompted extensive research into microbial degradation and value-added recycling. However, the lack of hosts with high PET degradation efficiency suitable for value-added recycling poses a significant challenge to achieving a circular economy. In this study, we investigated the influence of terephthalic acid (TPA) metabolic regulation in Ideonella sakaiensis on PET degradation, aiming to engineer a host with enhanced PET degradation capabilities. Our results revealed that I. sakaiensis with deficient TPA metabolism exhibited a significantly reduced PET degradation capability. Gene transcription analysis further revealed a correlation between the transcription levels of TPA metabolism-related genes and those of PET hydrolysis-related genes. By engineering I. sakaiensis to accelerate TPA metabolism, we achieved a 46.9% increase in PET degradation, with the weight loss of PET rising from 58.0   mg to 85.2   mg (83.6% weight loss of PET). This represents the highest level of microbial PET degradation achieved at room temperature to date. This newly discovered metabolic regulation and enhanced PET degradation in I. sakaiensis provide a novel perspective for improving microbial PET degradation and further increase the potential for achieving a closed-loop process that converts waste PET into high-value chemicals.