2025-01-16 オックスフォード大学
Schematic of the sustainable bioprocess for hydrogen bioproduction. Shewanella oneidensis MR-1 uses hydrogenase to catalyse H2 synthesis from protons and electrons, powered by light and green electricity. Image credit: Wei Huang.
<関連情報>
- https://www.ox.ac.uk/news/features/green-fuels-breakthrough-bio-engineering-bacteria-become-hydrogen-nanoreactors
- https://www.pnas.org/doi/abs/10.1073/pnas.2404958121
バクテリアのバイオナノリアクターで効率的な水素製造を実現 Engineering bionanoreactor in bacteria for efficient hydrogen production
Weiming Tu, Ian P. Thompson, and Wei E. Huang
Proceedings of the National Academy of Sciences Published:July 10, 2024
DOI:https://doi.org/10.1073/pnas.2404958121
Significance
Hydrogen production through water splitting has been substantially improved by engineering the nanoscale periplasmic space (20 to 30 nm) of Shewanella oneidensis MR-1, transforming it into a highly effective bionanoreactor. This design concentrated protons and electrons, enhancing hydrogen production. The integration of reduced graphene oxide (rGO), MtrCAB complex, and iron sulfide (FeS) nanoparticles established an effective electron transfer chain from the electrode to the periplasm. The introduction of Gloeobacter rhodopsin and canthaxanthin boosted proton pumping into the periplasm under light. This system, catalyzed by the overexpression of [FeFe]-hydrogenase and powered by both electricity and light, achieved a Faraday efficiency of 80% for hydrogen production. This periplasmic bionanoreactor marks an advancement in sustainable synthetic biology.
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.
