Cloning, expression, and functional characterization of an organophosphates insecticides degrading gene (opdC) from a potential probiotic Lactobacillus plantarum WCP931

Abstract

An organophosphorus (OP) insecticides degrading strain Lactobacillus plantarum WCP931, harboring OP hydrolase (OpdC) gene, was isolated during kimchi fermentation. The strain WCP931 appeared a significant survival rate of 51 to 96% under the artificial gastric acidic condition at pH 2 to 3 after 3 h. The opdC gene consisting 831 bp encoding 276 amino acids was cloned from the strain WCP907. The recombinant Escherischia coli harboring opdC gene depleted 77% chlorpyrifos (CP) in M9 medium after 6 days of incubation. The OpdC enzyme represents a novel member of GHSQG family of esterolytic enzymes or new Opd group. The OpdC molecular mass was estimated to be approximately 31 kDa in SDS-PAGE and showed maximum activity at 40 οC with pH 6. However, the mutated OpdC (Ser116 → Ala116) enzyme had no activity towards OP insecticides and ρ-nitrophenol-β-butyrate. Importantly, relative activity of OpdC against P-O bond insecticides was higher than P-S bond insecticide, which indicated its broad substrate specificity. It is suggested that opdC gene of strain WCP931 play role for the biodegradation of OP insecticides during kimchi fermentation.