Membraneless organelles assembled by AuNPs-enzyme integration in non-photosynthetic bacteria: Achieving high specificity and selectivity for solar hydrogen production

The emergence of semiartificial photosynthesis holds great promise for improving light energy capture and conversion efficiency. However, achieving high product specificity and selectivity in semiartificial photosynthetic systems remains a challenge. In this study, we employed genetic engineering techniques to construct a membraneless organelle in E. coli, serving as the photoreaction carrier. The self-assembly of photosensitizers and hydrogenase within the carrier has successfully established a semiartificial photosynthetic model characterized by high product specificity and selectivity. In this model system, electrons were directly transferred to hydrogenase upon AuNPs light excitation in membraneless organelle, eliminating the need for additional electron mediators and bypassing the use of intracellular NADH/NAD+ as a reducing agent to avoid byproduct formation. The semiartificial photosynthetic system demonstrated an 11782-fold and 40-fold increase in hydrogen production compared to bare AuNPs and the empty vector E. coli hybrid system, respectively. This membraneless organelle holds the potential to robustly support the specific synthesis of high-energy-density, value-added compounds through solar energy conversion.