title: Biodegradation of organophosphorus pesticides by surface-expressed organophosphorus hydrolase.
abstract: Organophosphorus hydrolase (OPH) was displayed and anchored onto the surface of Escherichia coli using an Lpp-OmpA fusion system. Production of the fusion proteins in membrane fractions was verified by immunoblotting with OmpA antisera. Inclusion of the organophosphorus hydrolase signal sequence was necessary for achieving enzymatic activity on the surface. More than 80% of the OPH activity was located on the cell surface as determined by protease accessibility experiments. Whole cells expressing OPH on the cell surface degraded parathion and paraoxon very effectively without any diffusional limitation, resulting in sevenfold higher rates of parathion degradation compared with whole cells with similar levels of intracellular OPH. Immobilization of these live biocatalysts onto solid supports could provide an attractive means for pesticide detoxification in place of immobilized enzymes, affording a reduced diffusional barrier.
authors.affiliation: Department of Chemical Engineering, University of California, Riverside 92521, USA.
authors.forename: R D
authors.initials: RD
authors.lastname: Richins
authors.forename: I
authors.initials: I
authors.lastname: Kaneva
authors.forename: A
authors.initials: A
authors.lastname: Mulchandani
authors.forename: W
authors.initials: W
authors.lastname: Chen
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000096:biosynthesis* / Q000235:genetics; D001673:Biodegradation, Environmental / Q000187:drug effects; D019149:Bioreactors; D015153:Blotting, Western; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics; D007306:Insecticides / Q000378:metabolism*; D008970:Molecular Weight; D010261:Paraoxon / Q000378:metabolism; D010278:Parathion / Q000378:metabolism; D010744:Phosphoric Monoester Hydrolases / Q000096:biosynthesis* / Q000235:genetics; D010957:Plasmids; D016133:Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000096:biosynthesis
chemical_list: D001425:Bacterial Outer Membrane Proteins; D007306:Insecticides; D011994:Recombinant Proteins; D010278:Parathion; C045290:phosphorylphosphatase; D010744:Phosphoric Monoester Hydrolases; D010261:Paraoxon