State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China.
State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China.
J Hazard Mater. 2022 Oct 15;440:129709. doi: 10.1016/j.jhazmat.2022.129709. Epub 2022 Aug 3.
Polyethylene (PE) is one of the most widely used plastics. However, the chemical inertness, inefficient recycling, and random landfilling of PE waste have caused serious pollution to the natural environment. In this study, a series of laccase-mediator systems (LMS) were constructed by combination of two laccases from Botrytis aclada (BaLac) and Bacillus subtilis (BsLac) with three synthetic mediators (ABTS, HBT, and TEMPO) to oxidize LDPE films (UVPE) pretreated with high-temperature UV irradiation. Scanning electron microscopy showed aging phenomena such as etching, fragmentation, and cracking on the surface of the UVPE films after LMS incubation. The FTIR results showed that LMS-UVPE added new oxygen-containing functional groups such as -OH, -CO, and CC. High-temperature gel chromatography confirmed that the average reduction in weight-average molecular weight (Mw) was approximately 40% for the BaLac experimental group. GC-MS analysis showed the presence of oxygen-containing products, such as aldehydes, ketones, and alcohols, in the reaction mixture. To verify the oxidation process UVPE degradation by LMS, we inferred three possible pathways by combined analysis of the oxidation products of LMS on UVPE and model substrates oleic acid and squalene.
聚乙烯（PE）是应用最广泛的塑料之一。然而，PE 化学惰性、回收效率低下以及随意填埋所造成的废弃物对自然环境造成了严重的污染。在这项研究中，通过组合两种来自 Botrytis aclada（BaLac）和枯草芽孢杆菌（BsLac）的漆酶与三种合成介体（ABTS、HBT 和 TEMPO）构建了一系列漆酶-介体系统（LMS），以氧化经高温紫外线照射预处理的低密度聚乙烯薄膜（UVPE）。扫描电子显微镜显示，LMS 孵育后，UVPE 薄膜表面出现老化现象，如蚀刻、碎片和开裂。傅里叶变换红外光谱（FTIR）结果表明，LMS-UVPE 添加了新的含氧官能团，如-OH、-CO 和 CC。高温凝胶色谱法证实 BaLac 实验组的重均分子量（Mw）平均降低了约 40%。GC-MS 分析表明反应混合物中存在含氧产物，如醛、酮和醇。为了验证 LMS 对 UVPE 降解的氧化过程，我们通过对 LMS 在 UVPE 和油酸、角鲨烯等模型底物上的氧化产物进行综合分析，推断出三条可能的途径。
