Genetically Engineered Hybrid Biosystem for Highly Efficient Conversion from Glucose to Hydrogen

The integration of semiconductor nanoparticles and bacteria presents an enticing method to augment fermentative hydrogen production by leveraging solar energy as an additional driving force. However, there remains significant room for improvement in effectively using and transforming substrates within the biohybrid system. Here, a new type of engineered Escherichia coli (E. coli) strain is constructed by multigene knockout of hycA, ldhA, and frdD to strengthen the flux of pyruvate to formate. Subsequently, upon intracellular biomineralization in the presence of a cadmium source and a selenium source, CdSe_xS_1-x nanoparticles could be specially formed inside the engineered strain, and then a high conversion efficiency from glucose to hydrogen is achieved, as high as 1.86 mol·H₂·mol^-1·G^-1 (93% of the theoretical value from glucose to H₂), which currently boasts the highest conversion ratio among biohybrid systems. Therefore, it is anticipated that such a study could contribute a promising way to break through the bottleneck of biological hydrogen production efficiency.