School of Biotechnology, Jiangnan University, Jiangsu Wuxi, China.
Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China.
Lett Appl Microbiol. 2020 Sep;71(3):235-241. doi: 10.1111/lam.13312. Epub 2020 Jun 2.
The polyethylene terephthalate hydrolase (PETase) has been proved to have a high activity to degrade polyethylene terephthalate (PET), but few studies have been carried on its secretion in Bacillus subtilis. In this study, the coding gene of PETase, which was isolated from the Ideonella sakaiensis, was synthesized and expressed in B. subtilis. Then, we evaluated the ability of five Bacillus signal peptides to enhance PETase secretion by B. subtilis. The results indicated that the SP -induced secretion of PETase was the highest, and its activity against p-Nitrophenyl palmitate was about fourfold that of the natural signal peptide SP . The weak promoter P43 provided sufficient time for translation and folding of PETase, resulting in increased extracellular expression. Use of P43 and SP in combination yielded the greatest bis-(2-hydroxyethyl) terephthalate degradation and PET-film etching activity due to maximized secretion of PETase by B. subtilis. Our findings will facilitate biodegradation of PET plastic. SIGNIFICANCE AND IMPACT OF THE STUDY: High-level expression of polyethylene terephthalate hydrolase (PETase) facilitates biodegradation of PET. In this study, the expression elements, signal peptide and promoter, in the secretory expression system, were optimizing for maximizing secreted expression of PETase in Bacillus subtilis. The constructed strains yielded the greatest bis-(2-hydroxyethyl) terephthalate degradation and PET-film etching activities.
聚对苯二甲酸乙二醇酯水解酶（PETase）已被证明具有很高的活性，可以降解聚对苯二甲酸乙二醇酯（PET），但很少有研究涉及它在枯草芽孢杆菌中的分泌。在本研究中，从解淀粉芽孢杆菌中分离得到的 PETase 编码基因在枯草芽孢杆菌中进行了合成和表达。然后，我们评估了五种枯草芽孢杆菌信号肽增强枯草芽孢杆菌 PETase 分泌的能力。结果表明，SP 诱导的 PETase 分泌最高，其对 p-硝基苯棕榈酸酯的活性约为天然信号肽 SP 的四倍。弱启动子 P43 为 PETase 的翻译和折叠提供了足够的时间，从而增加了细胞外表达。由于枯草芽孢杆菌对 PETase 的最大分泌，使用 P43 和 SP 的组合产生了最大的双（2-羟乙基）对苯二甲酸降解和 PET 薄膜蚀刻活性。我们的发现将有助于 PET 塑料的生物降解。研究的意义和影响：聚对苯二甲酸乙二醇酯水解酶（PETase）的高水平表达促进了 PET 的生物降解。在本研究中，对分泌表达系统中的表达元件、信号肽和启动子进行了优化，以最大限度地提高枯草芽孢杆菌中 PETase 的分泌表达。构建的菌株产生了最大的双（2-羟乙基）对苯二甲酸降解和 PET 薄膜蚀刻活性。
