Molecular identification and cloning of organophosphate degradation gene in some bacterial isolates

ABSTRACT

Seventeen local bacterial isolates which can hydrolyze a wide range of organophosphate [OP] insecticides were purified. They were reduced to ten different isolates based on their RAPD pattern and protein profile and termed as ASM-1 through ASM-10. Chemical assay and bioassay revealed that the isolate ASM-5 was the best isolate in chlorpyrifos degradation. The morphological and molecular identification characterized ASM-5 as Agrobacterium tumefaciens. A gene encoding a protein involved in OP hydrolysis was cloned and sequenced from A. tumefaciens ASM-5. This gene [named opdA] had sequence similarity about 98.7% with the A. tumefaciens opd gene. The coding sequence of the gene was sub cloned down stream an inducible expression promoter to evaluate the gene-enzyme system responsible for its OP-hydrolyzing activity. The biological activity of OPDA protein became more efficient compared to OPDA native protein