Yao Jiaxin, Jiang Yaru, Hao Mengyao, Liang Mengxiang, Gu Zhenghua, Zhang Liang, Guo Zhongpeng
National Engineering Research Center of Gereal Fermentation and Biomanufacturing, Jiangnan University, Wuxi 214122, Jiangsu, China.
JITRI Future Food Technology Research Institute Co., Ltd., Yixing 214205, Jiangsu, China.
Sheng Wu Gong Cheng Xue Bao. 2024 Oct 25;40(10):3705-3721. doi: 10.13345/j.cjb.230745.
Polyethylene terephthalate (PET) is a largely-produced polymer worldwide. However, its extensive waste generation and resistance to degradation pose significant environmental concerns. Consequently, there is considerable interest in researching enzymatic degradation of PET. Relevant studies have shown that the addition of a carbohydrate binding module (CBM) can increase the affinity between the enzyme and the substrate, enhancing the enzyme's degradation ability. In order to develop more efficient PET hydrolytic enzymes, this study introduced carbohydrate binding domains (CBMs) from different families with different substrate affinities into the PET-degrading enzyme LCC-ICCG. High crystallinity PET powder and amorphous PET film were used as substrates to characterize the degradation efficiency of the modified enzymes, aiming to explore the enzyme with the optimal degradation ability. The results showed that the fusion of type B CBM reduced the degradation rate and value of the enzyme towards PET, while the introduction of type A and type C CBMs significantly improved the degradation rate of the enzyme towards the film-like substrate. The degradation rate and value of PET were also enhanced, especially with the fusion enzyme LCC-ICCG-CBM9-2, which showed an over 10-fold increase in the degradation rate compared to the original enzyme LCC-ICCG. Therefore, this study demonstrates that by introducing type A and type C CBMs, the degradation rate and thermal stability of LCC-ICCG towards film-like PET can be improved, addressing the issue of its low activity and enabling more effective PET degradation. This research provides support for plastic degradation technology and contributes to environmental conservation efforts.
聚对苯二甲酸乙二酯（PET）是全球产量巨大的聚合物。然而，其大量产生的废弃物以及难以降解的特性引发了严重的环境问题。因此，对PET酶促降解的研究备受关注。相关研究表明，添加碳水化合物结合模块（CBM）可以增加酶与底物之间的亲和力，提高酶的降解能力。为了开发更高效的PET水解酶，本研究将具有不同底物亲和力的不同家族的碳水化合物结合结构域（CBM）引入到PET降解酶LCC - ICCG中。使用高结晶度PET粉末和非晶态PET薄膜作为底物来表征修饰后酶的降解效率，旨在探索具有最佳降解能力的酶。结果表明，B型CBM的融合降低了该酶对PET的降解速率和 值，而引入A型和C型CBM则显著提高了该酶对薄膜状底物的降解速率。PET的降解速率和 值也有所提高，尤其是融合酶LCC - ICCG - CBM9 - 2，其降解速率相比原始酶LCC - ICCG提高了10倍以上。因此，本研究表明，通过引入A型和C型CBM，可以提高LCC - ICCG对薄膜状PET的降解速率和热稳定性，解决其活性低的问题，实现更有效的PET降解。本研究为塑料降解技术提供了支持，有助于环境保护工作。
