Environmental and ecological hazards caused by the accumulation of polyethylene terephthalate (PET) are becoming a global concern. The use of enzymes to address the plastic crisis has achieved many successes, but the difficulty in degrading high-crystallinity PET has limited its application. Numerous studies have investigated the degradation of PET with arbitrary crystallinity to bis-2-(2-hydroxyethyl) terephthalate (BHET) using chemical pre-treatment methods such as glycolysis, but few have tested its biocompatibility with enzymatic alliances.
RESULTS
Herein, we report the enzymatic characterization and subsequent engineering of the state-of-the-art IsPETasePA and MHETase (where MHET is mono(2-hydroxyethyl) terephthalate), a dual-enzyme system which can be used for the degradation from BHET to a single-product terephthalate (TPA). Modulators, including surfactants, organic solvents and metal ions, enhanced the enzyme activity of IsPETasePA and MHETase by up to 1.1-fold and 2.3-fold, respectively. 100% TPA yield (BHET of 25 g L−1) was achieved within 5 h. We also analyzed the mechanism of optimal ion modulator modification by dynamics simulation, and it synergistically achieved enhancement of MHET degradation ability by improving stability and binding energy.
期刊介绍:
Journal of Chemical Technology and Biotechnology(JCTB) is an international, inter-disciplinary peer-reviewed journal concerned with the application of scientific discoveries and advancements in chemical and biological technology that aim towards economically and environmentally sustainable industrial processes.