Interfacial engineering-based colonization of biofilms on polyethylene terephthalate (PET) surfaces: Implications for whole-cell biodegradation of microplastics

Microplastic pollution has become a significant environmental issue. One of the most important sources and components of microplastics is polyester fabric - polyethylene terephthalate (PET). Because the catalytic depolymerization of PET typically requires specific conditions such as alkaline environments, specific solvents, or high temperatures, there is an urgent need for a simpler, eco-friendly solution with high degradation efficiency for managing the vast amounts of PET textile waste. In this study, Comamonas testosterone F4, which we screened and cultivated to grow using PET as the sole carbon source, was utilized as a whole-cell biocatalyst. The bioprocess was optimized through interfacial engineering, which leveraged dynamic supramolecular interactions and molecular recognition at the PET-enzyme interface. Biofilms were more effectively formed on the surfaces of PET@Span-80 and PET@TRE. Through supramolecular interactions, Span-80 and Trehalose lipids (TRE), which serve as host and guest chemicals, readily adhere to the PET surface. Compared to untreated PET fibers, PET surfaces treated with biodegradable surfactants showed increased hydrophilicity, which facilitated bacterial colonization and enhanced bacterial and enzymatic activity on PET. Furthermore, combining PET@Span-80 and a strategy for renewing bacterial cultures (RBC) resulted in a high-efficiency degradation effect over an extended degradation period. The weight loss of PET increased from 2.23 % to 5.67 % after four weeks of degradation. A more efficient method for the biodegradation of PET was proposed by our team. The developed interfacial enhancement system provides a practical approach to accelerate the degradation of PET fabric waste, thereby mitigating the substantial environmental impact of polyester textile waste.