Abstract:
Hydrogen production through water splitting is a vital strategy for renewable and sustainable clean energy. In this study, we developed an approach integrating nanomaterial engineering and synthetic biology to establish a bionanoreactor system for efficient hydrogen production. The periplasmic space (20 to 30 nm) of an electroactive bacterium, Shewanella oneidensis MR-1, was engineered to serve as a bionanoreactor to enhance the interaction between electrons and protons, catalyzed by hydrogenases for hydrogen generation. To optimize electron transfer, we used the microbially reduced graphene oxide (rGO) to coat the electrode, which improved the electron transfer from the electrode to the cells. Native MtrCAB protein complex on S. oneidensis and self-assembled iron sulfide (FeS) nanoparticles acted in tandem to facilitate electron transfer from an electrode to the periplasm. To enhance proton transport, S. oneidensis MR-1 was engineered to express Gloeobacter rhodopsin (GR) and the light-harvesting antenna canthaxanthin. This led to efficient proton pumping when exposed to light, resulting in a 35.6% increase in the rate of hydrogen production. The overexpression of native [FeFe]-hydrogenase further improved the hydrogen production rate by 56.8%. The bionanoreactor engineered in S. oneidensis MR-1 achieved a hydrogen yield of 80.4 μmol/mg protein/day with a Faraday efficiency of 80% at a potential of -0.75 V. This periplasmic bionanoreactor combines the strengths of both nanomaterial and biological components, providing an efficient approach for microbial electrosynthesis.
摘要:
通过水分解制氢是可再生和可持续清洁能源的重要战略。在这项研究中,我们开发了一种集成纳米材料工程和合成生物学的方法,以建立一个生物阳极反应器系统,用于高效的制氢。电活性细菌的周质空间(20至30nm),ShewanellaoneidensisMR-1被设计用作生物阳极反应器,以增强电子和质子之间的相互作用,用氢化酶催化制氢。为了优化电子转移,我们使用微生物还原的氧化石墨烯(rGO)来涂覆电极,这改善了电子从电极到细胞的转移。在S.oneidensis上的天然MtrCAB蛋白复合物和自组装的硫化铁(FeS)纳米颗粒串联起作用,以促进电子从电极转移到周质。为了增强质子传输,S.onidensisMR-1被设计为表达视紫红质(GR)和光捕获天线角黄素。当暴露于光线时,这导致了有效的质子泵,导致制氢速率增加35.6%。天然[FeFe]氢化酶的过表达进一步提高了56.8%的产氢率。在S.oneidensisMR-1中设计的生物阳极反应器在-0.75V的电势下实现了80.4μmol/mg蛋白质/天的氢产量,法拉第效率为80%。这种周质生物阳极反应器结合了纳米材料和生物成分的优势,为微生物电合成提供了一种有效的方法。