Co-metabolic enzymes and pathways of 3-phenoxybenzoic acid degradation by Aspergillus oryzae M-4.
Co-metabolic enzymes and pathways of 3-phenoxybenzoic acid degradation by Aspergillus oryzae M-4.
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DOI：
10.1016/j.ecoenv.2019.109953
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发表时间：
2019-11
影响因子：
6.8
通讯作者：
Jiayuan Zhao;Dongying Jia;Yuanlong Chi;K. Yao
中科院分区：
文献类型：
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作者：
Jiayuan Zhao;Dongying Jia;Yuanlong Chi;K. Yao
作为拟除虫菊酯的中间代谢物，3-苯氧苯甲酸（3-PBA）比其母体化合物毒性更大，在牛奶、土壤和人类尿液中都被检测到。3-PBA可以通过微生物降解代谢，但参与3-PBA降解的微生物共代谢酶和途径尚不清楚。本研究探讨了aspergillusoryzaem -4共代谢降解3-PBA的酶类型和可能的途径。诱导参与3-PBA及其中间代谢物共代谢降解的酶，除儿茶酚降解酶外，存在于细胞外和细胞内。这些氧化酶的抑制剂和诱导剂被用来研究3-PBA及其中间代谢物共代谢降解所需的酶。3-PBA通过木质素过氧化物酶（LiP）的催化作用羟基化生成3-羟基-5-苯氧苯甲酸。苯酚和没食子酸是3-PBA的代谢物，在细胞色素P450 （CYP450）和LiP的催化作用下，通过裂解醚键产生。苯酚可经LiP转化为儿茶酚；儿茶酚和没食子酸在双加氧酶和LiP作用下裂解成长链烯烃酸或烯烃醛。在玉米粉中，一些酶活化剂如FeCl3、4-茴香酸、戊曲醇和高碘酸钠似乎可以改善3-PBA的降解。研究结果为3-PBA在食物和环境中的共代谢降解提供了可靠的途径和特征。
As an intermediate metabolite of pyrethroids, 3-phenoxybenzoic acid (3-PBA) is more toxic than its parent compounds and has been detected in milk, soil, and human urine. 3-PBA can be metabolized through microbial degradation, but the microbial co-metabolic enzymes and pathways involved in 3-PBA degradation are unclear. This study investigated the enzymes types and possible pathways in the co-metabolic degradation of 3-PBA byAspergillusoryzaeM-4. The enzymes involved in co-metabolic degradation of 3-PBA and its intermediate metabolites were induced, and existed extracellularly and intracellularly except the catechol-degrading enzyme. Inhibitors and inducers of these oxidases were used to examine the enzymes required for co-metabolic degradation of 3-PBA and its intermediate metabolites. 3-PBA is hydroxylated to produce 3-hydroxy-5-phenoxy benzoic acid through the catalytic actions of lignin peroxidase (LiP). Phenol and gallic acid, the metabolites of 3-PBA, are produced via cleavage of an ether bond under the catalytic actions of cytochrome P450 (CYP450) and LiP. Phenol can be converted to catechol by LiP; catechol and gallic acid are cleaved to form long-chain olefin acid or olefin aldehyde by dioxygenase and LiP. In corn flour, some of these enzyme activators such as FeCl3, 4-cumaric acid, veratryl alcohol and sodium periodate appeared to improve 3-PBA degradation. The results provide a reliable pathway and characteristics for co-metabolic microbial degradation of 3-PBA in food and the environment.