State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, PR China.
State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, PR China; Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211816, PR China.
Environ Res. 2023 Dec 1;238(Pt 2):117240. doi: 10.1016/j.envres.2023.117240. Epub 2023 Sep 30.
Bis (2-hydroxyethyl) terephthalate (BHET) is one of the main compounds produced by enzymatic hydrolysis or chemical depolymerization of polyethylene terephthalate (PET). However, the lack of understanding on BHET microbial metabolism is a main factor limiting the bio-upcycling of PET. In this study, BHET-degrading strains of Rhodococcus biphenylivorans GA1 and Burkholderia sp. EG1 were isolated and identified, which can grow with BHET as the sole carbon source. Furthermore, a novel esterase gene betH was cloned from strain GA1, which encodes a BHET hydrolyzing esterase with the highest activity at 30 °C and pH 7.0. In addition, the co-culture containing strain GA1 and strain EG1 could completely degrade high concentration of BHET, eliminating the inhibition on strain GA1 caused by the accumulation of intermediate metabolite ethylene glycol (EG). This work will provide potential strains and a feasible strategy for PET bio-upcycling.
双（2-羟乙基）对苯二甲酸酯（BHET）是通过酶解或化学解聚聚对苯二甲酸乙二醇酯（PET）得到的主要化合物之一。然而，对 BHET 微生物代谢的认识不足是限制 PET 生物循环利用的主要因素。本研究从邻苯二甲酸二羟乙酯（GA1）和伯克霍尔德氏菌（EG1）中分离并鉴定了能够以 BHET 为唯一碳源生长的降解菌株。此外，从菌株 GA1 中克隆了一种新型酯酶基因 betH，该基因编码的 BHET 水解酯酶在 30°C 和 pH7.0 时具有最高活性。此外，包含菌株 GA1 和菌株 EG1 的共培养物可以完全降解高浓度的 BHET，消除了中间代谢物乙二醇（EG）积累对菌株 GA1 的抑制作用。这项工作将为 PET 的生物循环利用提供潜在的菌株和可行的策略。
