Abstract:Abstract: [Objective] The study aimed at establishing the bacterial luciferase: FMN-NADH oxidoreductase bioluminescent system in vitro and evaluating its potential for quantitative detection of NADH. [Methods] By optimizing the amount of substrates, we set up the coupled luciferase:FMN-NADH oxidoreductase bioluminescent system in vitro, based on the crude extract from Photobacterium leiognathi YL. [Results] The in vitro coupled bacterial luciferase:FMN-NADH oxidoreductase bioluminescent system was: 1mL crude extract, 27 mmol/L Dodecane 100 μL, 10 mmol/L FMN-Na 0.5 μL and 0.14 mmol/L NADH 300 μL. Furthermore, we developed a method for quantitative detection of NADH according to the bioluminescence of NADH catalyzed of bacterial luciferase: FMN-NADH oxidoreductase system in vitro. A good linear relationship of NADH concentration was in a range of 1.0×10-10 to 1.0×10-8 mol/L. [Conclusion] The bacterial luciferase:FMN-NADH oxidoreductase system used to measure NADH concentration was a good attempt to detect living bacterial cells in the fields of environment, food sanitation and other related.