Biodegradation of highly crystallized poly(ethylene terephthalate) through cell surface codisplay of bacterial PETase and hydrophobin

The process of recycling poly(ethylene terephthalate) (PET) remains a major challenge due to the enzymatic degradation of high-crystallinity PET (hcPET). Recently, a bacterial PET-degrading enzyme, PETase, was found to have the ability to degrade the hcPET, but with low enzymatic activity. Here we present an engineered whole-cell biocatalyst to simulate both the adsorption and degradation steps in the enzymatic degradation process of PETase to achieve the efficient degradation of hcPET. Our data shows that the adhesive unit hydrophobin and degradation unit PETase are functionally displayed on the surface of yeast cells. The turnover rate of the whole-cell biocatalyst toward hcPET (crystallinity of 45%) dramatically increases approximately 328.8-fold compared with that of purified PETase at 30 degrees C. In addition, molecular dynamics simulations explain how the enhanced adhesion can promote the enzymatic degradation of PET. This study demonstrates engineering the whole-cell catalyst is an efficient strategy for biodegradation of PET. High-crystallinity poly(ethylene terephthalate) is a major recycling challenge. Here, the authors show an engineered whole-cell biocatalyst showing adhesive hydrophobin and PETase on the surface of cells, for biodegradation of PET.

Automated summary

This study presents an engineered whole-cell biocatalyst for the efficient degradation of high-crystallinity poly(ethylene terephthalate) (PET). The whole-cell biocatalyst displays both adhesive hydrophobin and degradation unit PETase on the surface of yeast cells, significantly increasing the turnover rate compared to purified PETase. Molecular dynamics simulations explain how enhanced adhesion promotes the enzymatic degradation of PET.