Adam Nicole, Schlicht Stefanie, Han Yuchen, Bechelany Mikhael, Bachmann Julien, Perner Mirjam
Molecular Biology of Microbial Consortia, Biocenter Klein Flottbek, University of Hamburg, Hamburg, Germany.
Department of Chemistry and Pharmacy, Friedrich-Alexander University of Erlangen-Nürnberg, Interdisciplinary Center for Nanostructured Films (IZNF), Erlangen, Germany.
Front Bioeng Biotechnol. 2020 Jun 4;8:567. doi: 10.3389/fbioe.2020.00567. eCollection 2020.
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 TiO-coated polyacrylonitrile fiber electrode. Our results highlight the tremendous potential of enzymes derived from uncultured microorganisms for applications in energy conversion and storage technologies.
如果通过水电解生产氢气并在燃料电池中利用能够以高能效和非贵金属电催化剂实现，那么氢气在未来可以成为可再生能源的有利载体。我们以前所未有的方式将结构化电极与来自未培养且因此大多难以获取的微生物主体（>99%）的氢转化酶进行了新颖组合，以应对这一挑战。具有大比表面积的几何形状明确的电极能够实现低过电位和高能量效率。酶促析氢电催化剂被用作贵金属的替代品。这些酶是从表现出动态氢和氧浓度的热液喷口的环境微生物DNA（宏基因组）中获取的，并通过最近开发的基于活性的新型筛选工具进行回收。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。这避免了培养源生物体的需要，而培养源生物体是利用微生物酶时的主要瓶颈。一种源自宏基因组的氢转化酶分散在涂有TiO的聚丙烯腈纤维电极上时表现出高活性和异常高的稳定性。我们的结果突出了未培养微生物来源的酶在能量转换和存储技术中的巨大应用潜力。
