Nicotine aerobic degradation

The aerobic degradation of nicotine produces an A-methylpyrrolidine as the first metabolite by dehydrogenation. This is then hydroxylated at the benzylic carbon atom by an FAD-containing oxidase (Dai et al. 1968), and the y-A-methylaminobutyrate that is produced by fission of the A-methylpyrolidine ring is demethylated by an oxidase to 4-aminobutyrate (Chiribau et al. 2004). 

As for the aerobic degradation of pyridines, hydroxylation of the heterocyclic ring is a key reaction in the anaerobic degradation of azaarenes by Clostridia. Whereas in Clostridium barkeri, the end products are carboxylic acids, CO2, and ammonium, the anaerobic sulfate-reducing Desulfococcus niacinii degraded nicotinate completely to CO2 (Imhoff-Stuckle and Pfennig 1983), although the details of the pathway remain incompletely resolved. 

E. (2008) Deciphering the genetic determinants for aerobic nicotinic acid degradation the nic cluster from Pseudomonas putida KT2440. Proc. Natl. Acad. Sci. U.S.A., 105 (32), 11329-11334. 

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