Coexpression of two detoxifying pesticide-degrading enzymes in a genetically engineered bacterium

Abstract

Degradation of pesticides is usually beneficial, since the reactions that destroy pesticides convert most pesticide residues in the environment to inactive, less toxic, harmless compounds. This paper describes a novel strategy using a coexpression vector for the purpose of developing bacteria that can detoxify different pesticides. The vector pETDuet was designed for coexpression of two target genes simultaneously. The organophosphate hydrolase gene (opd) from Flavobacterium sp. and carboxylesterase B1 gene (b1) from Culex pipiens were cloned in the coexpression vector. The expressed enzymes of OPH and B1 had a molecular mass of approximately 35 and 65 kDa, respectively. A single microorganism was capable of producing both enzymes for degradation of organophosphorus, carbamate and pyrethroid pesticides. The technical capability of genetically engineering bacteria with more enzymes should open up new opportunities for extending the wide range of pesticides that can be biodegraded in the future. © 2006 Elsevier Ltd. All rights reserved.