Light‐Driven Butyrate Production by a Probiotic <i>Clostridium tyrobutyricum</i> Enabled by a Cell‐Semiconductor Hybrid Interface

ABSTRACT Butyrate, a valuable short‐chain fatty acid, serves as a natural preservative, flavor enhancer, and gut health modulator in the food and feed industries. However, its sustainable microbial production is constrained by the low yield and selectivity inherent to conventional fermentation processes, primarily due to intracellular redox and energy limitations. To address this, we developed a light‐driven probiotic system by integrating in situ biomineralized cadmium sulfide (CdS) nanoparticles with metabolically engineered Clostridium tyrobutyricum . This hybrid interface enables direct injection of photogenerated electrons into cellular metabolism, boosting the intracellular NADH/NAD + ratio by 51% and effectively reprogramming the redox state. Consequently, the system achieved a 33.2% increase in butyrate yield (0.437 vs. 0.328 g/g) and elevated product selectivity from 89.5% to 95.7%. This work demonstrates a green and energy‐efficient strategy for enhancing the bioproduction of food‐grade butyrate, offering a novel platform for advancing light‐powered fermentation in food biotechnology.