Selective and Sequential Catalysed Depolymerisation of Polyester Plastics

向循环塑料经济过渡对于节约资源、保留材料价值和防止猖獗的污染至关重要。酶降解塑料，或生物回收，为目前的机械和化学回收方法提供了一种新的选择，对于难以回收的塑料废物，如聚合物聚合物混合物，是一个很有前途的选择。定向进化是开发新型塑料降解酶的一种强有力的工程策略；先前的工作探索了一种活性和耐热的PETase的定向进化。我的新工作旨在扩大目前酶促塑料降解的底物范围，包括聚（双酚a）碳酸酯（BPA-PC），一种每年生产100万吨的工程热塑性塑料。BPA-PC通常与其他水解不稳定的聚合物如PET和PBT混合，使高选择性的BPA-PC解聚合酶成为一个有吸引力的靶标。为此，已鉴定出一种双酚a - pc降解酶，并正在进行第一轮定向进化。

Transitioning to a circular plastics economy is essential for the conservation of resources, retention of material value, and prevention of rampant pollution. Enzymatic plastic degradation, or biological recycling, offers a novel alternative to current mechanical and chemical recycling methods and is a promising option for difficult-to-recycle plastic waste, such a polymer-polymer blends. Directed evolution is a powerful engineering strategy in developing novel plastic degrading enzymes; previous work explored the directed evolution of an active and thermostable PETase. My new work seeks to broaden the current substrate scope of enzymatic plastic degradation to include poly(bisphenol-A) carbonate (BPA-PC), an engineering thermoplastic produced on a million ton per annum scale. BPA-PC is commonly blended with other hydrolytically labile polymers such as PET and PBT, making a highly selective BPA-PC depolymerase an attractive target. To this end, a BPA-PC degrading enzyme has been identified, and a first round of directed evolution is underway.