Plastic
Degradation
In this study,Rhodococcus was engineered to degrade PET plastics and convert them into protocatechuic acid efficiently
Plastic pollution is a growing global environmental problem.
Plastic has been a source of pollution in many environments,from Mount Everest to the ocean floor.
According to the European Plastics Association, global plastic production increases from about 1.5 million tons per year in 1950 to an estimated 275 million metric tons in 2010 and 359 million metric tons in 2018.Countries with maritime coastlines discharge between 4.8 and 12.7 million metric tons into the ocean yearly. At least 5.25 trillion plastic particles ,weighing about 244,000 metric tons,are estimated to float on or near the sea.
Currently, chemical or physical degradation methods of PET plastic not only cause secondary pollution to the environment but are also not conducive to the effective use of plastics to realize their resources.
Therefore, we constructed a dual-enzyme fusion system PETase-MHETase in Rhodococcus opacus PD630 and optimized different secreted promoter, signal peptides and enhancers to achieve highly efficient secretory expression of PETase-MHETase and efficient degradation of PET plastics. In addition, we also introduced 1, 2-dioxygenase to further convert the product TPA into bulk product protocatechuic acid to realize the renewable utilization of PET plastics and effectively reduce environmental pollution.
