title: Regulation of Hydroxylation and Nitroreduction Pathways during Metabolism of the Neonicotinoid Insecticide Imidacloprid by Pseudomonas putida.
abstract: Imidacloprid (IMI) is mainly metabolized via nitroreduction and hydroxylation pathways, which produce different metabolites that are toxic to mammals and insects. However, regulation of IMI metabolic flux between nitroreduction and hydroxylation pathways is still unclear. In this study, Pseudomonas putida was found to metabolize IMI to 5-hydroxy and nitroso IMI and was therefore used for investigating the regulation of IMI metabolic flux. The cell growth time, cosubstrate, dissolved oxygen concentration, and pH showed significant effect on IMI degradation and nitroso and 5-hydroxy IMI formation. Gene cloning and overexpression in Escherichia coli proved that P. putida KT2440 aldehyde oxidase mediated IMI nitroreduction to nitroso IMI, while cytochrome P450 monooxygenase (CYP) failed to improve IMI hydroxylation. Moreover, E. coli cells without CYP could hydroxylate IMI, demonstrating the role of a non-CYP enzyme in IMI hydroxylation. Thus, the present study helps to further understand the environmental fate of IMI and its underlying mechanism.
authors.affiliation: Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Science, Nanjing Normal University , Nanjing 210023, People's Republic of China.
authors.forename: Tian-Qi
authors.initials: TQ
authors.lastname: Lu
authors.affiliation: Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Science, Nanjing Normal University , Nanjing 210023, People's Republic of China.
authors.forename: Shi-Yun
authors.initials: SY
authors.lastname: Mao
authors.affiliation: Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Science, Nanjing Normal University , Nanjing 210023, People's Republic of China.
authors.forename: Shi-Lei
authors.initials: SL
authors.lastname: Sun
authors.affiliation: Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Science, Nanjing Normal University , Nanjing 210023, People's Republic of China.
authors.forename: Wen-Long
authors.initials: WL
authors.lastname: Yang
authors.affiliation: Nanjing Institute of Environmental Sciences , Ministry of Environmental Protection, Nanjing 210042, People's Republic of China.
authors.forename: Feng
authors.initials: F
authors.lastname: Ge
authors.affiliation: Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Science, Nanjing Normal University , Nanjing 210023, People's Republic of China.
authors.forename: Yi-Jun
authors.initials: YJ
authors.lastname: Dai
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001673:Biodegradation, Environmental; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism; D006900:Hydroxylation; D007093:Imidazoles / Q000378:metabolism*; D007306:Insecticides / Q000378:metabolism*; D053858:Metabolic Networks and Pathways; D000073943:Neonicotinoids; D009574:Nitro Compounds / Q000378:metabolism*; D016958:Pseudomonas putida / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D007093:Imidazoles; D007306:Insecticides; D000073943:Neonicotinoids; D009574:Nitro Compounds; C082359:imidacloprid; D003577:Cytochrome P-450 Enzyme System
keywords: Pseudomonas putida; aldehyde oxidase; hydroxylation; imidacloprid; nitroreduction