[Isolation and identification of a type strain bacteria with the highest ability to produce organophosphorus acid anhidrase]

ABSTRACT

In Iran, Organ phosphorus pesticides such as chloropyrifos and diazinon are widely used in agriculture. These compounds inhibit activity of cholinesterase in nearly irreversible manner resulting in malfunction of nerve impulse transmission. This result in humans can produce illness or even death. Therefore, the present study aims to isolate various bacterial strains in specified contaminated regions. We selected one of the isolates that contain the highest OP-hydrolyzing capability for using such strain, in decontaminating environmentally harmful OP residues. In this study, vast waters from chemical factories and contaminated agricultural soil samples were used for isolation of several bacterial strains that contain OPAA enzyme are capable of utilizing chloropyrifos and diazinon as a source of carbon and phosphorus by selective enrichment on mineral salt medium [MSM], which contains chloropyrifos or diazinon. One strain was selected for analysis of degradation ability with growth studies and HPLC technique and characterization by Bergey's manual. From vast water and soil, ten bacterial strains were isolated using chloropyrifos and diazinon as source of carbon and phosphorus. One of them named IHU strain4; grows most rapidly and luxuriously and displays the highest organophosphate-hydrolyzing capability. On the basis of morphological and biochemical characteristics, the bacterial isolate was identified as a member of the genus pseudomonas. From these findings, it can be concluded that the isolated bacterial strain is able to utilize Organ phosphorus pesticides as a source of carbon and phosphorus. Utilization of these compounds by soil microorganisms is a crucial phenomenon by which these compounds are removed from the environment, thus, preventing environmental pollution. Results from the present study suggest that the isolated bacterial strain may be used for remediation of pesticide-contamination