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 viable 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 is innocent of altering microbial behavior. Here we report unexpected metabolic rewiring induced by water-splitting electrochemistry in H2-oxidizing acetogenic bacterium Sporomusa ovata that challenges such a classic view. We found that the planktonic S. ovata is more efficient in utilizing reducing equivalent for ATP generation and hence CO2 fixation in the materials-biology hybrids, supported by our 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.