Complete biodegradation of chlorpyrifos by engineered Pseudomonas putida cells expressing surface-immobilized laccases
Complete biodegradation of chlorpyrifos by engineered Pseudomonas putida cells expressing surface-immobilized laccases
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表达表面固定化漆酶的工程恶臭假单胞菌细胞对毒死蜱的完全生物降解
DOI：
10.1016/j.chemosphere.2016.05.031
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发表时间：
2016-08-01
期刊：
影响因子：
8.8
通讯作者：
Li, Lin
中科院分区：
文献类型：
--
作者：
Liu, Jin;Tan, Luming;Li, Lin
在农业和园艺中长期滥用类毒死蜱农药已造成严重的土壤或水污染，并对全球生态系统构成威胁。在这项研究中，研究了一种耐溶剂细菌，恶臭假单胞菌MB285，与表面显示的细菌漆酶，生物降解毒死蜱的能力。通过高效液相色谱和气相色谱质谱分析，对降解产物进行了成分分析，结果表明MB285能够通过直接生物降解完全去除毒死蜱。暂时检测到两种中间代谢物，即3,5,6-三氯-2-吡啶醇（TCP）和磷酸二乙酯，验证了表面漆酶和某些细胞酶对毒死蜱的联合和逐步降解，而纯化的游离漆酶则不完全将毒死蜱降解为TCP。降解反应可以在很宽的pH值（2-7）和温度（5-55℃）范围内进行，而不需要Cu2+。以秀丽隐杆线虫为指示生物的生物测定表明，该培养基可通过降解完全解毒毒死蜱。此外，工程细胞表现出高的重复降解能力和良好的连续降解循环性能，以及对含有毒死蜱的实际废水的高降解能力。因此，所开发的系统具有较高的降解能力和性能，是解决毒死蜱污染的一种改进方法。(C) 2016 Elsevier Ltd.版权所有。
The long-term abuse use of chlorpyrifos-like pesticides in agriculture and horticulture has resulted in significant soil or water contamination and a worldwide ecosystem threat. In this study, the ability of a solvent-tolerant bacterium, Pseudomonas putida MB285, with surface-displayed bacterial laccase, to biodegrade chlorpyrifos was investigated. The results of compositional analyses of the degraded products demonstrate that the engineered MB285 was capable of completely eliminating chlorpyrifos via direct biodegradation, as determined by high-performance liquid chromatography and gas chromatography mass spectrometry assays. Two intermediate metabolites, namely 3,5,6-trichloro-2-pyridinol (TCP) and diethyl phosphate, were temporarily detectable, verifying the joint and stepwise degradation of chlorpyrifos by surface laccases and certain cellular enzymes, whereas the purified free laccase incompletely degraded chlorpyrifos into TCP. The degradation reaction can be conducted over a wide range of pH values (2-7) and temperatures (5-55 degrees C) without the need for Cu2+. Bioassays using Caenorhabditis elegans as an indicator organism demonstrated that the medium was completely detoxified of chlorpyrifos by degradation. Moreover, the engineered cells exhibited a high capacity of repeated degradation and good performance in continuous degradation cycles, as well as a high capacity to degrade real effluents containing chlorpyrifos. Therefore, the developed system exhibited a high degradation capacity and performance and constitutes an improved approach to address chlorpyrifos contamination in chlorpyrifos-remediation practice. (C) 2016 Elsevier Ltd. All rights reserved.