Catalyzes the NADH-dependent reduction of a broad spectrum of quinone substrates, generating the corresponding hydroquinones. Highly prefers NADH to NADPH as a reducing substrate. Also displays a small NADH oxidase activity. Does not exhibit nitronate monooxygenase activity; is inactive against propionate 3-nitronate, 3-nitropropionate, nitroethane, 1-nitropropane, 2-nitropropane, and the anionic forms ethylnitronate, propyl-1-nitronate, and propyl-2-nitronate. Has no azoreductase activity since it is not able to reduce the azo dye methyl red with NADH. May be required to maintain an appropriate [NAD(+)]/[NADH] ratio for the catabolism of fatty acids in P.aeruginosa PAO1. a quinone + H(+) + NADH = a quinol + NAD(+) Binds 1 FMN per subunit. kcat is 14 sec(-1) with 5,8-dihydroxy-1,4-naphthoquinone as substrate. kcat is 17 sec(-1) with 5-hydroxy-1,4-naphthoquinone as substrate. kcat is 16 sec(-1) with 2-methyl-5-hydroxy-1,4-naphthoquinone as substrate. kcat is 16 sec(-1) with 2-methyl-1,4-naphthoquinone as substrate. kcat is 6 sec(-1) with 2-methoxy-1,4-naphthoquinone as substrate. kcat is 27 sec(-1) with 1,4-benzoquinone as substrate. kcat is 24 sec(-1) with 2-methyl-5,6-dimethoxy-1,4-benzoquinone as substrate. kcat is 28 sec(-1) with 2,3,4,6-tetramethyl-1,4-benzoquinone as substrate. Monomer. The two-electron reduction of quinones by this enzyme occurs through a Ping-Pong-Bi-Bi steady-state kinetic mechanism. Belongs to the nitronate monooxygenase family. Was reported to be a 2-nitropropane dioxygenase, the previous name for nitronate monooxygenase (PubMed:16682407). However, later experiments demonstrate that this protein does not have any nitronate monooxygenase activity, the activity reported by Ha et al. was likely due to the non-enzymatic reaction of propyl-2-nitronate with oxygen (PubMed:27502282).