UiO-66-Mediated Light-Driven Regeneration of Intracellular NADH in Clostridium tyrobutyricum to Strengthen Butyrate Production

With the increasing depletion of petroleum and fossil resources, the development of green, low-carbon recycling systems has become the main goal for achieving carbon neutrality. Biohybrid photosynthesis systems have been confirmed to reduce carbon loss and promote microbial metabolism to achieve high yields of chemicals. Here, we used UiO-66, an excellent photocatalyst, to increase the intracellular pool of reduced nicotinamide adenine dinucleotide hydrogen (NADH) for butyrate production in Clostridium tyrobutyricum. The NADH/NAD⁺ ratio increased by 62% in the UiO-66 and C. tyrobutyricum hybrid system compared to the other groups under illumination, which resulted in a 25% increase in butyrate production (11.71 ± 0.16 vs 9.36 ± 0.14 g/L). The system improved the utilization rate of carbon sources and reduced carbon loss. Proteomic analysis also revealed that UiO-66 enhanced the intracellular NADH supply under illumination, leading to an increase in butyrate production. Thus, this system provides an outstanding strategy for improving the conversion of organic carbon into useful chemicals that helps to achieve energy savings and reduce emissions.