title: Degradation kinetics of caffeine and related methylxanthines by induced cells of Pseudomonas sp.
abstract: In this study, the kinetics of degradation of caffeine and related methylxanthines by induced cells of Pseudomonas sp. was performed. The kinetics data showed that degradation of caffeine, theobromine, and 7-methylxanthine followed Michealis-Menten kinetics. The values of K (m) are low for caffeine and 7-methylxanthine and high for theobromine. Degradation of caffeine and theobromine was enhanced in the presence of NADH and NADPH, whereas the degradation of 7-methylxanthine was unaffected. Among the various metal ions tested, Fe(2+) was found to enhance the rate of degradation for all three substrates, whereas Zn(2+) and Cu(2+) inhibited the degradation of caffeine and theobromine but not 7-methylxanthine. The differences in kinetic parameters and cofactor requirement suggest the possibility of the involvement of more than one N-demethylases in the caffeine catabolic pathway in Pseudomonas sp. The induced cells can serve as effective biocatalysts for the development of biodecaffeination techniques.
authors.affiliation: Department of Biotechnology, Indian Institute of Technology-Madras, Chennai, 600 036, India.
authors.forename: Swati Sucharita
authors.initials: SS
authors.lastname: Dash
authors.forename: Sathyanarayana N
authors.initials: SN
authors.lastname: Gummadi
mesh_terms: D002110:Caffeine / Q000378:metabolism*; D003067:Coenzymes / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007700:Kinetics; D008670:Metals / Q000494:pharmacology; D009243:NAD / Q000494:pharmacology; D009249:NADP / Q000494:pharmacology; D011549:Pseudomonas / Q000378:metabolism*; D013805:Theobromine / Q000378:metabolism*; D014970:Xanthines / Q000378:metabolism*
chemical_list: D003067:Coenzymes; D004791:Enzyme Inhibitors; D008670:Metals; D014970:Xanthines; D009243:NAD; D002110:Caffeine; D009249:NADP; C064273:7-methylxanthine; D013805:Theobromine