Pickering Emulsion Biocatalysis with Engineered Living Cells for Degrading Polycarbonate Plastics

Abstract The efficient degradation of plastics remains a pressing environmental challenge due to their inherent resistance to breakdown. While biocatalysis offers a promising approach for sustainable and effective plastic degradation, the inherently low solubility of plastics in aqueous systems severely limits the efficiency of enzymatic reactions. To address this issue, we developed a biocompatible polymer coating strategy to engineer living cell surfaces, enabling the stabilization of Pickering emulsions for over 192 h and significantly enhancing plastic accessibility to biocatalysts. Leveraging this platform, Escherichia coli (E. coli) cells containing overexpressed Candida antarctica Lipase B performed well by dispersing at the emulsion interface of water and toluene, facilitating the efficient biodegradation of polycarbonate (PC) plastics. Under optimized reaction conditions (pH 9, 45 °C), this Pickering emulsion system achieved efficient PC degradation, producing up to 4.5 mm bisphenol A within 72 h—far exceeding the performance of biphasic systems using native E. coli cells. The findings highlight the transformative potential of surface‐engineered whole‐cell catalysts in addressing environmental challenges, particularly plastic waste remediation.