title: Isolation of an isocarbophos-degrading strain of Arthrobacter sp. scl-2 and identification of the degradation pathway.
abstract: Isocarbophos is a widely used organophosphorus insecticide that has caused environmental pollution in many areas. However, degradation of isocarbophos by pure cultures has not been extensively studied, and the degradation pathway has not been determined. In this paper, a highly effective isocarbophos-degrading strain, scl-2, was isolated from isocarbophos-polluted soil. Strain scl-2 was preliminarily identified as Arthrobacter sp. based on its morphological, physiological, and biochemical properties, as well as 16S rDNA analysis. Strain scl-2 could utilize isocarbophos as its sole source of carbon and phosphorus for growth. One hundred mg/l isocarbophos could be degraded to a nondetectable level in 18 h by scl-2 in cell culture, and isofenphos-methyl, profenofos, and phosmet could also be degraded. During the degradation of isocarbophos, the metabolites isopropyl salicylate, salicylate, and gentisate were detected and identified based on MS/MS analysis and their retention times in HPLC. Transformation of gentisate to pyruvate and fumarate via maleylpyruvate and fumarylpyruvate was detected by assaying for the activities of gentisate 1,2- dioxygenase (GDO) and maleylpyruvate isomerase. Therefore, we have identified the degradation pathway of isocarbophos in Arthrobacter sp. scl-2 for the first time. This study highlights an important potential use of the strain scl-2 for the cleanup of environmental contamination by isocarbophos and presents a mechanism of isocarbophos metabolism.
authors.affiliation: Key Laboratory of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, 210095, Nanjing, Jiangsu Province, China.
authors.forename: Li
authors.initials: L
authors.lastname: Rong
authors.forename: Xinqiang
authors.initials: X
authors.lastname: Guo
authors.forename: Kai
authors.initials: K
authors.lastname: Chen
authors.forename: Jianchun
authors.initials: J
authors.lastname: Zhu
authors.forename: Shunpeng
authors.initials: S
authors.lastname: Li
authors.forename: Jiandong
authors.initials: J
authors.lastname: Jiang
mesh_terms: D001173:Arthrobacter / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D001673:Biodegradation, Environmental; D049308:Dioxygenases / Q000378:metabolism; D007306:Insecticides / Q000378:metabolism*; D008294:Malathion / Q000031:analogs & derivatives* / Q000378:metabolism; D053858:Metabolic Networks and Pathways; D008969:Molecular Sequence Data; D063086:Organothiophosphates / Q000378:metabolism; D009946:Organothiophosphorus Compounds / Q000378:metabolism; D010706:Phosmet / Q000378:metabolism; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012459:Salicylates / Q000737:chemistry / Q000378:metabolism; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism; D013997:Time Factors; D019745:cis-trans-Isomerases / Q000378:metabolism
chemical_list: D007306:Insecticides; D063086:Organothiophosphates; D009946:Organothiophosphorus Compounds; D012336:RNA, Ribosomal, 16S; D012459:Salicylates; D012989:Soil Pollutants; C056490:methyl isofenphos; C549713:isocarbophos; C024273:profenofos; D049308:Dioxygenases; C026247:gentisate 1,2-dioxygenase; D019745:cis-trans-Isomerases; C046138:maleylpyruvate isomerase; D008294:Malathion; D010706:Phosmet