Identification and characterization of a novel phthalate-degrading hydrolase from a soil metagenomic library
Identification and characterization of a novel phthalate-degrading hydrolase from a soil metagenomic library
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DOI：
10.1016/j.ecoenv.2019.110148
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发表时间：
2020-03-01
影响因子：
6.8
通讯作者：
Xin, Zhihong
中科院分区：
文献类型：
--
作者：
Qiu, Jiarong;Zhang, Yueqi;Xin, Zhihong
邻苯二甲酸酯对环境和人类健康的影响引起了公众的关注。我们使用功能驱动筛选从宏基因组文库中鉴定出一种新的邻苯二甲酸酯降解水解酶EstJ6。系统发育分析表明，EstJ6是IV家族酯酶的成员。在40℃和pH 7.5条件下，EstJ6对邻苯二甲酸二烷基酯和单烷基酯具有较高的水解活性（128 U/mg）。EstJ6不仅能水解具有简单侧链的普通邻苯二甲酸酯，还能水解具有复杂长侧链的邻苯二甲酸二乙基己酯和邻苯二甲酸一乙基己酯。位点定向突变表明，EstJ6的催化三联体残基由Ser146、Glu240和His270组成。因此，EstJ6是一种很有前途的生物降解酶，我们的研究说明了宏基因组方法在农业、食品和生物技术应用中鉴定酶编码基因的优势。
Phthalate esters have raised public concerns owing to their effects on the environment and human health. We identified a novel phthalate-degrading hydrolase, EstJ6, from a metagenomic library using function-driven screening. Phylogenetic analysis indicated that EstJ6 is a member of family IV esterases. EstJ6 hydrolyzed various dialkyl and monoalkyl phthalate esters, and exhibited high hydrolytic activity (128 U/mg) toward di butyl phthalate at 40 degrees C and pH 7.5. EstJ6 hydrolyzed not only common phthalate esters with simple side chains but also diethylhexyl phthalate and monoethylhexyl phthalate, which have complex and long side chains. Sitedirected mutagenesis indicated that the catalytic triad residues of EstJ6 consists of Ser146, Glu240, and His270. EstJ6 is therefore a promising biodegradation enzyme, and our study illustrates the advantages of a metagenomic approach in identifying enzyme-coding genes for agricultural, food, and biotechnological applications.