National Energy R&D Center for Biorefinery, Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China.
National Energy R&D Center for Biorefinery, Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China.
J Environ Manage. 2024 Sep;368:122217. doi: 10.1016/j.jenvman.2024.122217. Epub 2024 Aug 14.
The rapid increase in global plastic consumption, especially the worldwide use of polyethylene terephthalate (PET), has caused serious pollution problems. Due to the low recycling rate of PET, a substantial amount of waste accumulates in the environment, which prompts a growing focus on enzymatic degradation for its efficiency and environmentally friendliness. This study systematically designed and modified a cutinase, Est1 from Thermobifida alba AHK119, known for its potential of plastic-degradation at high temperatures. Additionally, the introduction of clustering algorithms provided the ability to understand and modify biomolecules, to accelerate the process of finding the optimal mutations. K-means was further proceeded based on the positive mutations. After comprehensive screening for thermostability and activity mutation sites, the dominant mutation Est1_5M (Est1 with the mutations of N213M, T215P, S115P, Q93A, and L91W) exhibited satisfying degradation ability for commercial PET bottles. The results showed that Est1_5M achieved a degradation rate of 90.84% in 72 h, 65-fold higher than the wild type. This study offers reliable theoretical and practical support for the development of efficient PET-degrading enzymes, providing a reference for plastic pollution management.
全球塑料消费量的迅速增长，特别是全球范围内对聚对苯二甲酸乙二醇酯（PET）的使用，造成了严重的污染问题。由于 PET 的回收利用率较低，大量的废物在环境中积累，这促使人们越来越关注其高效、环保的酶降解方法。本研究系统地设计和修饰了一种来自嗜热真菌白腐菌 AHK119 的角质酶 Est1，该酶因其在高温下具有塑料降解潜力而备受关注。此外，聚类算法的引入提供了理解和修饰生物分子的能力，加速了寻找最佳突变的过程。在此基础上，进一步采用 K-means 算法对阳性突变进行了分析。经过对热稳定性和活性突变位点的综合筛选，发现具有 N213M、T215P、S115P、Q93A 和 L91W 突变的 Est1_5M（Est1 突变体）对商用 PET 瓶表现出令人满意的降解能力。结果表明，Est1_5M 在 72 小时内的降解率达到 90.84%，比野生型提高了 65 倍。本研究为高效 PET 降解酶的开发提供了可靠的理论和实践支持，为塑料污染治理提供了参考。
