Fig. 4.

Optimization of the universal biosynthesis pathway of S. oneidensis (Module 3). a A depiction of the overexpressed genes in the universal biosynthesis pathway (Module 3). b Plasmids that included the assemblage of genes (nadD and nadE) in the universal biosynthesis pathway of Module 3. c Voltage output in MFCs of the above S. oneidensis recombinant strains. d Quantitative measurements of the intracellular NAD⁺, NADH, and total NAD(H/⁺) levels of these strains under anaerobic cultures. e Rewiring the universal biosynthesis pathway by introducing a heterogeneous nadM pathway in addition to the native universal nadD–nadE pathway (Module 3). f A depict of the overexpressed heterogeneous nadM gene in the native universal biosynthesis pathway (Module 3). Plasmids that included the assemblage of genes (nadM, nadD, and nadE) in the universal biosynthesis pathway of Module 3. g Voltage output in MFCs of the above S. oneidensis recombinant strains, respectively. h Quantitative measurements of the intracellular NAD⁺, NADH, and total NAD(H/⁺) levels of these strains under anaerobic cultures