title: Utilization and degradation of imazaquin by a naturally occurring isolate of Arthrobacter crystallopoietes.
abstract: A species of bacteria that is capable of utilizing imazaquin as the sole carbon source was isolated from soil with repeated imazaquin applications, and was identified as Arthrobacter crystallopoietes (designated as strain "WWX-1"). This isolate degrades imazaquin as high as 200 microg ml-1, and the estimated dissipation half-lives increased from 1.51 d for the treatment at 50 microg ml-1 to 4.75 d for 200 microg ml-1. Optimal growth of WWX-1 in mineral salt medium with 50 microg ml-1 imazaquin was obtained at 35 degrees C and a pH of 5.0. Growth of WWX-1 was also observed in mineral salt medium with the addition of other imidazolinone herbicides such as imazethapyr and imazapyr, but not with different classes of herbicides such as metsulfuron-methyl. Two imazaquin metabolites were detected, and spectral analysis with HPLC-MS, 1H NMR, and IR revealed one metabolite with a molecular weight (MW) of 199 as quinoline-2,3-dicarboxylic anhydride. We propose that A. crystallopoietes (WWX-1) could serve as an efficient biodegradation system for remediation of water and soils that are heavily contaminated with imazaquin or other structurally similar chemicals.
authors.affiliation: Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, Central China Normal University, Wuhan 430079, PR China.
authors.forename: Xuedong
authors.initials: X
authors.lastname: Wang
authors.forename: Xiujuan
authors.initials: X
authors.lastname: Liu
authors.forename: Huili
authors.initials: H
authors.lastname: Wang
authors.forename: Qiaoxiang
authors.initials: Q
authors.lastname: Dong
mesh_terms: D001173:Arthrobacter / Q000254:growth & development / Q000378:metabolism*; D001673:Biodegradation, Environmental; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D003470:Culture Media; D006540:Herbicides / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007093:Imidazoles / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D011804:Quinolines / Q000378:metabolism*; D012988:Soil Microbiology; D013055:Spectrophotometry, Infrared; D013696:Temperature
chemical_list: D003470:Culture Media; D006540:Herbicides; D007093:Imidazoles; D011804:Quinolines; C057728:imazaquin