Quorum Sensing-Based Long-Term Biodegradation of Polyethylene Terephthalate in Contaminated Soil by Engineered and .

Long-term biodegradation of soil microplastics such as polyethylene terephthalate (PET) remains inadequately addressed due to the limited expression of efficient PET degrading enzymes in engineered bacteria. Here, we developed a quorum-sensing (QS)-based protein expression system (XylS-LuxI/LuxR) that enhanced reporter green fluorescent protein (GFP) expression by 44-fold in (). Using this system, we constructed whole-cell PET biodegraders expressing PET hydrolases (FASTPETase-MHETase) and leaf-branch compost cutinase (LCC) in and (). Soil-based assays using crude enzymes and XylS-QS-LCC cells showed >80% degradation of bis(2-hydroxyethyl) terephthalate (BHET) within 30 min. Furthermore, Agde-LCC was identified as the most effective signal peptide (SP) for protein secretion in , whereas LCC without a SP performed best in . Engineered achieved up to 63% PET nanoparticle degradation over 30 days, while reached 42.3% within 20 days in nonsterilized soil, substantially outperforming wild-type controls and indicating synergistic interactions with native microbiota. These results demonstrate that XylS-QS-based systems enable efficient, self-regulated whole-cell PET biodegradation in soil environments, providing new insights for the development of efficient biodegradation strategies of environmental plastic waste.