Fig. 2

Pyridine pathway of nicotine degradation in Arthrobacter sp. involves key enzymes: nicotine dehydrogenase (NDH), 6-hydroxy-l-nicotine oxidase (6-HLNO), 6-hydroxy-d-nicotine oxidase (6HDNO), ketone oxidase (KO), ketone dehydrogenase (KDH), 2,6-dihydroxy-pseudooxynicotine hydrolase (2,6-DHPONH), 2,6-dihydroxypyridine-3-hydroxylase (2,6-DHPH), γ-N-methylaminobutyrate oxidase (MABO), monoamine oxidase (MAO), amine oxidase (AO), and succinic semialdehyde dehydrogenase (SsaDH)