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Bioremediation of Organophosphorus Pesticides by Surface‐Expressed Carboxylesterase from Mosquito on Escherichia coli
Author(s) -
Zhang Jianliang,
Lan Wensheng,
Qiao Chuanling,
Jiang Hong
Publication year - 2004
Publication title -
biotechnology progress
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.572
H-Index - 129
eISSN - 1520-6033
pISSN - 8756-7938
DOI - 10.1021/bp049903c
Subject(s) - carboxylesterase , lysis , escherichia coli , chemistry , microbiology and biotechnology , esterase , hydrolase , biochemistry , chromatography , biology , enzyme , gene
The insecticide resistance‐associated esterase, carboxylesterase B1 (CaE B1), from mosquito was used to degrade the organophosphorus compounds. To eradicate the need for enzyme purification and minimize the resistance to mass transport of the substrate and product across the cell membranes, the CaE B1 was displayed on the cell surface of Escherichia coli fused to the C‐terminus of the ice nucleation protein (INP). The presence of CaE B1 on the bacterial cell surface was verified by SDS‐PAGE, Western blotting analysis, and immunofluorescence microscopy. More than 50% of active CaE B1 is exported across the membrane and anchored onto the cell surface as determined by proteinase accessibility and cell fractionation experiments. In contrast, only a 6% drop in activity for proteinase K‐treated cells was detected from E.coli cells containing pET‐B1. From the degradation experiment, more than 80% of the malathion was degraded by whole cells containing plasmid pUC‐NC‐B1. Constitutive expression of CaE B1 on the surface using INPNC resulted in no cell lysis, and the suspended cultures also exhibited good stability. Because of their high biodegradation activity and superior stability, these “live biocatalysts” are promising for detoxification of organophosphorus pesticides.