Microbial Electrosynthetic Biohybrid System to Synergistically Supply Electrons and CO 2 to Rhodopseudomonas palustris for Lycopene Production

ABSTRACT Microbial electrosynthesis (MES) systems aim to use electroactive microorganisms (EAMs) to achieve electricity‐driven CO 2 fixation for biosynthesis of multicarbon chemicals. However, the low efficiencies of extracellular electron transfer (EET) and CO 2 assimilation of EAMs remain the essential limiting factors that restrict performance of MES systems. Herein, we developed an electrosynthetic biohybrid system to synergistically supply electrons and CO 2 to Rhodopseudomonas palustris (an EAM) for lycopene biosynthesis. Intracellular carbon and energy fluxes were redirected by strengthening the lycopene biosynthesis pathway and blocking the nitrogen‐fixation pathway, resulting in 23‐fold increase in lycopene yield than that of the wild‐type R. palustris . To enhance extracellular transfer of CO 2 and electrons to R. palustris , metal‐organic frameworks (MOFs) with high CO 2 adsorption capacity were assembled with polydopamine on cell membrane to construct a biohybrid MES system, which produced 3.55 mg/L lycopene in two consecutive MES cycles, the highest lycopene production from CO 2 . Electrochemical and transcriptomic analyses revealed that the biohybrid MES system stimulated microbial metabolism including EET, the Calvin‐Benson‐Bassham cycle and lycopene biosynthesis, thereby improving CO 2 ‐to‐chemical conversion. This study demonstrated directional supply of electrons and CO 2 to EAMs enabled high‐performance MES systems, which also offered insights into the mechanisms underlying efficient CO 2 fixation and carbon‐negative biomanufacturing.