Biocatalytic properties of cell surface display laccase for degradation of emerging contaminant acetaminophen in water reclamation
Biocatalytic properties of cell surface display laccase for degradation of emerging contaminant acetaminophen in water reclamation
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DOI：
10.1002/bit.27214
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发表时间：
2019-12
影响因子：
3.8
通讯作者：
Ying Wu;Yingying Chen;Na Wei
中科院分区：
文献类型：
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作者：
Ying Wu;Yingying Chen;Na Wei
表面展示漆酶（SDL）生物催化剂，其中酶漆酶通过合成生物学展示在生物细胞的表面上，为开发用于从废水中去除新兴污染物的可持续技术提供了新的机会。本研究大力的SDL的生物催化性能相比，游离漆酶在去除新兴污染物对乙酰氨基酚（APAP），目的是了解表面展示对酶功能的影响，并确定克服潜在的限制的策略。SDL可以有效地删除APAP。添加氧化还原介体大大提高了去除效率。Michaelis-Menten动力学分析表明，氧化还原介体2，2-连氮双-3-乙基苯并噻唑啉-6-磺酸盐能够克服APAP进入SDL生物催化剂漆酶活性位点的限制。SDL对真实的二级出水中APAP的去除率高于乙酸盐缓冲液中的去除率，综合酶动力学分析表明，废水中存在氧化还原介导化合物。转化产物的分析表明，表面展示并没有改变漆酶功能的APAP转化机制。此外，SDL保留88%的初始活性后，六个重复的APAP生物转化反应。本研究结果为开发和实施SDL作为污染物处理应用的创新生物催化材料提供了科学依据。
The surface display laccase (SDL) biocatalyst, where the enzyme laccase is displayed on the surface of biological cells through synthetic biology, provides a new opportunity to develop sustainable technologies for removal of emerging contaminants from wastewater. This study vigorously characterized biocatalytic properties of the SDL in comparison to free laccase in removing emerging contaminant acetaminophen (APAP), with the aim to understand the effect of surface display on enzyme functionality and identify the strategy to overcome the potential limitation. The SDL could effectively remove APAP. Adding redox mediators substantially improved the removal efficiency. The Michaelis–Menten kinetic analysis showed that the redox mediator 2,2‐azinobis‐3‐ethylbenzothiazoline‐6‐sulfonate could overcome the limitation of APAP accessing the active site of laccase in the SDL biocatalyst. The APAP removal rate catalyzed by the SDL in real secondary wastewater effluent was higher than that in acetate buffer; comprehensive enzyme kinetic analysis provided clear evidence that there were redox mediating compounds in the wastewater. Analysis of transformation products revealed that surface display did not change laccase functionality in terms of APAP transformation mechanism. In addition, the SDL retained 88% of the initial activity after six repeated APAP biotransformation reactions. Results from this study provide a scientific basis for developing and implementing SDL as an innovative biocatalytic material for contaminant treatment applications.