title: An engineered microorganism can simultaneously detoxify cadmium, chlorpyrifos, and γ-hexachlorocyclohexane.
abstract: Many ecosystems are currently co-contaminated with heavy metals such as cadmium (Cd(2+) ) and pesticides such as chlorpyrifos (CP) and γ-hexachlorocyclohexane (γ-HCH). A feasible approach to remediate the combined pollution of heavy metals and pesticides is the use of γ-HCH degrading bacteria endowed with CP hydrolysis and heavy metal biosorption capabilities. In this work, a recombinant microorganism capable of simultaneously detoxifying Cd(2+) , CP, and γ-HCH was constructed by display of synthetic phytochelatins (EC20) and methyl parathion hydrolase (MPH) fusion protein on the cell surface of the γ-HCH degrading Sphingobium japonicum UT26 using the truncated ice nucleation protein (INPNC) as an anchoring motif. The surface localization of INPNC-EC20-MPH was verified by cell fractionation, Western blot analysis, immunofluorescence microscopy, and proteinase accessibility experiment. Expression of EC20 on the cell surface not only improved Cd(2+) binding but also alleviated the cellular toxicity of Cd(2+) . As expected, the rates of CP and γ-HCH degradation were reduced in the presence of Cd(2+) for cells without EC20 expression. However, expression of EC20 (higher Cd(2+) accumulation) significantly restored the levels of CP and γ-HCH degradation. These results demonstrated that surface display of EC20 enhanced not only Cd(2+) accumulation but also protected the recombinant strain against the toxic effects of Cd(2+) on CP and γ-HCH degradation.
authors.affiliation: State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, Tianjin, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China.
authors.forename: Huilei
authors.initials: H
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Jiang
authors.affiliation: State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Chuanling
authors.initials: C
authors.lastname: Qiao
authors.affiliation: State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, Tianjin, China.
authors.forename: Ruihua
authors.initials: R
authors.lastname: Liu
mesh_terms: D001673:Biodegradation, Environmental; D002104:Cadmium / Q000378:metabolism* / Q000633:toxicity; D004390:Chlorpyrifos / Q000378:metabolism* / Q000633:toxicity; D004785:Environmental Pollutants / Q000378:metabolism; D004787:Environmental Pollution; D000075322:Heavy Metal Poisoning; D001556:Hexachlorocyclohexane / Q000378:metabolism* / Q000633:toxicity; D008658:Inactivation, Metabolic; D010575:Pesticides / Q000378:metabolism* / Q000633:toxicity; D010744:Phosphoric Monoester Hydrolases / Q000235:genetics / Q000378:metabolism*; D054811:Phytochelatins / Q000235:genetics / Q000378:metabolism*; D011041:Poisoning; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D042301:Sphingomonadaceae / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*
chemical_list: D004785:Environmental Pollutants; D010575:Pesticides; D011993:Recombinant Fusion Proteins; D002104:Cadmium; D001556:Hexachlorocyclohexane; D054811:Phytochelatins; C524863:methyl parathion hydrolase, Sphingomonas; D010744:Phosphoric Monoester Hydrolases; D004390:Chlorpyrifos
keywords: Cadmium; Cell surface display; Chlorpyrifos; Sphingobium japonicum UT26; γ-Hexachlorocyclohexane