FIG 1.

Manipulation of the NADH-to-NAD⁺ ratio via the introduction of an NADH oxidase and a formate dehydrogenase into PA14. (A) Enzymatic reactions of the S. pneumoniae NADH oxygenase Nox^Sp and the C. boidinii formate dehydrogenase FDH1^Cb. (B) Enzymatic activity (in μmol per min and mg total protein) of both enzymes increased upon addition of increasing concentrations of β-d-1-thiogalactopyranoside (IPTG). The activities were measured in cell extracts. EV stands for cells carrying the empty vector. Significant differences were calculated by unpaired t test with Welch’s correction and are indicated with asterisks. ***, P < 0.001; ****, P < 0.0001. N.D., not determined.