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What is PET?

PET (Polyethylene Terephthalate) is a common thermoplastic polymer formed by the polymerization of terephthalic acid and ethylene glycol.

How can we tackle it?

Advantages:
High efficiency; breaks PET into repolymerizable monomers for closed-loop recycling
Disadvantages:
Needs harsh conditions, high energy use; catalysts hard to separate, prone to residue; downstream purification complex/costly, may have toxic by-products.

Advantages:
Simple operation, no chemical reagents, theoretically suitable for outdoor exposure
Disadvantages:
Strong light dependence; surface degradation mainly; uncontrollable safety; poor effect on non-transparent/thick-walled PET, narrow application range

Compared with the above two methods, biodegradation is the PET degradation technology with the greatest environmental potential:
Advantages:
① Environmentally friendly—relies on enzymes/microorganisms, with mild reactions and no toxic by-products, avoiding secondary pollution from the source;
② High resource value—can convert degradation products into high-value compounds, conforming to the circular economy;
③ Great application potential—although current issues such as low efficiency, high cost, and microbial specificity exist, these can be solved through technical optimization and are not fundamental limitations.

In summary, although biodegradation requires technical improvement, it is the most promising mainstream direction for solving PET pollution currently, relying on its core competitiveness of "environmental friendliness, resourcefulness, and sustainability".

How to change the current situation ?

Degradation

To address the issues of difficult recovery and poor stability of free PET-degrading enzymes, our study constructed a magnetic immobilized dual-enzyme (TfCa/Tfh) system. K5C was used as a template to prepare K5C@Fe₃O₄ via biomineralization; two self-assembly systems enabled the ordered immobilization of the dual enzymes. The optimal condition was 3.0M NaOH, and the sequential immobilization strategy could produce 1.2mM TPA. After 10 cycles, the system still retained 61% of its activity, which confirms its good operational stability and reusability potential.

Upgrading and Recycling

TPA

SUMMARY

Centered on "high synergy between bioinformatics modeling and wet experiments", the project advances PET resource utilization. It first uses wet experiments to build a dual-enzyme system for PET degradation, then employs modeling to screen key metabolic genes, verified by wet experiments to construct engineered bacteria that convert PET into high-value products. Forming a "PET degradation-detection-conversion-high-value recovery" closed loop, it highlights strong dry-wet integration and achieves a shift from non-recyclable to recyclable, offering an eco-friendly and economical solution.

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