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

Abstract

AbstractWe report a rationally designed membrane‐intercalating conjugated oligoelectrolyte (COE), namely COE‐IC, which endows aerobic N2‐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 15N2 atmosphere led to the enrichment of 15N‐containing intracellular metabolites, consistent with the products being generated from atmospheric N2.