A Broad Light‐Harvesting Conjugated Oligoelectrolyte Enables Photocatalytic Nitrogen Fixation in a Bacterial Biohybrid

Abstract We report a rationally designed membrane‐intercalating conjugated oligoelectrolyte (COE), namely COE‐IC , which endows aerobic N 2 ‐fixing bacteria Azotobacter vinelandii with a light‐harvesting ability that enables photosynthetic ammonia production. COE‐IC possesses an acceptor‐donor‐acceptor (A‐D‐A) type conjugated core, which promotes visible light absorption with a high molar extinction coefficient. Furthermore, COE‐IC spontaneously associates with A. vinelandii to form a biohybrid in which the COE is intercalated within the lipid bilayer membrane. In the presence of L‐ascorbate as a sacrificial electron donor, the resulting COE‐IC / A. vinelandii biohybrid showed a 2.4‐fold increase in light‐driven ammonia production, as compared to the control. Photoinduced enhancement of bacterial biomass and production of L‐amino acids is also observed. Introduction of isotopically enriched 15 N 2 atmosphere led to the enrichment of 15 N‐containing intracellular metabolites, consistent with the products being generated from atmospheric N 2 .