Engineering yeast surface display of cutinase from Paraphoma chrysanthemicola for polyester plastic biodegradation.

A yeast surface display system in Pichia pastoris GS115 was developed for cutinase PcCUT7 obtained from Paraphoma chrysanthemicola. GCW61, a glycosylphosphatidylinositol-modified cell wall protein, was used as the anchoring module. PcCUT7 was genetically fused to GCW61 and successfully displayed on the yeast cell surface. The surface-displayed PcCUT7 exhibited optimal activity at pH 8 and 30 °C. Compared to the free enzyme, surface-displayed PcCUT7 demonstrated enhanced thermal stability, improved alkaline tolerance, and greater resistance to inhibitory metal ions, organic solvents, and surfactants. Furthermore, it retained over 70% of its initial activity after five weeks of storage at 4 °C and maintained more than 50% activity after four reuse cycles. Functional assays demonstrated efficient degradation of polybutylene succinate films by surface-displayed PcCUT7, with 75.2 ± 2.8% weight loss within 60 h. The ease of preparation, high catalytic activity, and reusability of surface-displayed PcCUT7 highlight its potential as a cost-effective biocatalyst for the biodegradation of aliphatic polyesters.