Metagenomics Meets Electrochemistry: Utilizing the Huge Catalytic Potential From the Uncultured Microbial Majority for Energy-Storage
Metagenomics Meets Electrochemistry: Utilizing the Huge Catalytic Potential From the Uncultured Microbial Majority for Energy-Storage
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DOI：
10.3389/fbioe.2020.00567
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发表时间：
2020-06-04
影响因子：
5.7
通讯作者：
Perner, Mirjam
中科院分区：
文献类型：
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作者：
Adam, Nicole;Schlicht, Stefanie;Perner, Mirjam
如果利用高能效和非贵重电催化剂实现氢的水电解生产和在燃料电池中的利用，氢将在未来成为可再生能源的有利载体。在一种前所未有的新型组合中，结构化电极与氢转化酶来自未培养的，因此大部分难以接近的微生物（>99%），我们解决了这一挑战。具有大比表面积的几何定义电极允许实现低过电位和高能量效率。酶析氢电催化剂被用作贵金属的替代品。这些酶来自热液喷口的环境微生物DNA（宏基因组），显示出动态的氢和氧浓度，并通过最近开发的新型基于活性的筛选工具进行回收。该筛选使我们能够通过在替代宿主微生物中直接表达，从宏基因组中靶向目前未被识别的氢化酶。这规避了对源生物的培养的需要，这是利用微生物酶的主要瓶颈。一种氢转化宏基因组衍生酶分散在二氧化钛包覆的聚丙烯腈纤维电极上，表现出高活性和异常高的稳定性。我们的研究结果强调了从未经培养的微生物中提取的酶在能量转换和储存技术中的巨大潜力。
Hydrogen can in the future serve as an advantageous carrier of renewable energy if its production via water electrolysis and utilization in fuel cells are realized with high energy efficiency and non-precious electrocatalysts. In an unprecedented novel combination of structured electrodes with hydrogen converting enzymes from the uncultured and thus largely inaccessible microbial majority (>99%) we address this challenge. The geometrically defined electrodes with large specific surface area allow for low overpotentials and high energy efficiencies to be achieved. Enzymatic hydrogen evolution electrocatalysts are used as alternatives to noble metals. The enzymes are harnessed from the environmental microbial DNA (metagenomes) of hydrothermal vents exhibiting dynamic hydrogen and oxygen concentrations and are recovered via a recently developed novel activity-based screening tool. The screen enables us to target currently unrecognized hydrogenase enzymes from metagenomes via direct expression in a surrogate host microorganism. This circumvents the need for cultivation of the source organisms, the primary bottleneck when harnessing enzymes from microbes. One hydrogen converting metagenome-derived enzyme exhibited high activity and unusually high stability when dispersed on a TiO2-coated polyacrylonitrile fiber electrode. Our results highlight the tremendous potential of enzymes derived from uncultured microorganisms for applications in energy conversion and storage technologies.