The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, PR China.
The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, PR China.
J Biosci Bioeng. 2020 May;129(5):588-594. doi: 10.1016/j.jbiosc.2019.11.002. Epub 2019 Nov 21.
Recently, residual plasticizer phthalate esters (PAEs) in the different environments pose a serious health threat to humans and mammals. Biodegradation has been considered a promising and eco-friendly way to eliminate PAEs. In this study, a gene (baces04) encoding the novel PAEs hydrolase, carboxylesterase (BaCEs04), was screened from the genome of Bacillus velezensis SYBC H47 via bioinformatics analysis. Then, baces04 was cloned and expressed in Escherichia coli BL21 (DE3). BaCEs04 belonged to the esterase family VI. It contained a conserved domain (Gly-His-Ser-Leu-Gly) and a typical serine hydrolase catalytic site (Ser-Asp-His). The characterization of BaCEs04 showed that the activity was optimal at 60°C and pH 7.5. This enzyme also displayed high resistance to metal ions, organic solvents, and detergents. After treatment with BaCEs04 for 5 h, the degradation ratio of four different 1 mM PAEs, including dimethyl phthalate, diethyl phthalate, dipropyl phthalate, and dibutyl phthalate, was 32.4%, 50.5%, 77.9%, and 86.8%, respectively. The degradation products of four PAEs were identified as their corresponding monoalkyl phthalates. This is the first report that family VI esterase displaying PAE-hydrolysis activity. This study also proved that BaCEs04 could be used as an ideal candidate for the application in bioremediation and industry.
最近，不同环境中的残留塑化剂邻苯二甲酸酯（PAEs）对人类和哺乳动物构成了严重的健康威胁。生物降解被认为是消除 PAEs 的一种有前途且环保的方法。在这项研究中，通过生物信息学分析，从解淀粉芽孢杆菌 SYBC H47 的基因组中筛选到一个编码新型 PAEs 水解酶羧酸酯酶（BaCEs04）的基因。然后，克隆并在大肠杆菌 BL21（DE3）中表达了 baces04。BaCEs04 属于酯酶家族 VI，它包含一个保守结构域（Gly-His-Ser-Leu-Gly）和一个典型的丝氨酸水解酶催化位点（Ser-Asp-His）。BaCEs04 的特性研究表明，该酶在 60°C 和 pH7.5 时活性最佳。该酶还对金属离子、有机溶剂和洗涤剂表现出较高的抗性。用 BaCEs04 处理 5 小时后，四种不同 1mM PAEs（邻苯二甲酸二甲酯、邻苯二甲酸二乙酯、邻苯二甲酸二丙酯和邻苯二甲酸二丁酯）的降解率分别为 32.4%、50.5%、77.9%和 86.8%。四种 PAEs 的降解产物被鉴定为相应的单烷基邻苯二甲酸酯。这是首例报道家族 VI 酯酶具有 PAE 水解活性的研究。本研究还证明 BaCEs04 可以作为生物修复和工业应用的理想候选物。
