Integrated Omic Analysis Reveals Unexpected Metabolic Rewiring of CO₂ Fixation in H₂-Mediated Materials-Biology Hybrids

A hybrid approach combining water-splitting electrochemistry and H₂-oxidizing, CO₂-fixing microorganisms offers a promising solution of producing value-added chemicals from sunlight, water, and air. The classic wisdom without thorough examination to date assumes that the electrochemistry in such a H₂-mediated process does not affect microbial behavior. Here we report unexpected metabolic rewiring induced by water-splitting electrochemistry in H₂-oxidizing acetogenic bacterium <i>Sporomusa ovata</i> that challenges such a classic view. We found that the planktonic <i>S. ovata</i> in the materials-biology hybrids is more efficient in utilizing reducing equivalent for ATP generation and hence CO₂ fixation to acetate than in cells grown with H₂ supply, supported by integrated metabolomic and proteomic studies. These observations unravel previously underappreciated materials’ impact on microbial metabolism in seemingly simply H₂-mediated charge transfer between biotic and abiotic components. Such a deeper understanding at the materials-biology interface will foster advanced design of hybrid systems for sustainable chemical transformation.