Table 3.

Intracellular NADH oxidase activities, NAD (H) concentrations and ratio of NAD⁺ to NADH in MNR M3, MNR M3N1 and MNR M3N2

Strains	MNR M3	MNR M3N1	MNR M3N2
NADH oxidase activity (U/mg)	ND	0.32 ± 0.02	0.86 ± 0.02
NAD+ (μmol/g DCW)	9.34 ± 0.50	9.71 ± 0.33	9.11 ± 0.72
NADH (μmol/g DCW)	0.90 ± 0.15	0.44 ± 0.05	0.30 ± 0.02
Ratio of NAD+ to NADH	10.4	22.1	30.4

Biotransformation conditions: 50 mL fermentation medium in 250 mL shake flask, 30 °C, 140 r/min, 96 h. All experiments were performed in triplicate