Morteza khani, Farshid kafilzadeh
"Each year a lot of pesticides are entered into the environment through different ways. Diazinon (O,O-DiethylO-(2-Isopropyl-6-methyl-4-pyrimidyl) Phosphorothioate) is in fact an organophosphorus that is widely employed in agriculture. Initial environmental concerns for the effect of this pesticide in injury to birds, contamination of surface water and destructive effects on aquatic species exist. Diazinon and its metabolites have been paid atten-tion throughout the world during alarming studies on different aquatic systems. In this study, diazinon degrada-tion by Pseudomonas aeruginosa and Flavobacterium bacteria were evaluated. For the first stage, during two con-secutive seasons of the year samples were collected from the soils of three agricultural soil stations in Marvdasht city in Iran, Subsequently, counting the bacteria was done using Total Viable Plate Count (TVPC) and isolating the diazinon degrading bacteria. Eventually, Identifying diazinon degrading bacteria and the rate of de-composition by bacteria was measured using gas chromatography. Determining the growth of the isolated bacte-ria in different concentrations of diazinon was also performed to show the growth kinetics by studying their op-tical absorption. Our results showed that the Pseudomonas aeruginosa and Flavobacterium reduced the level of diazinon at level of p ≤ 0.05. Also, the growth of the bacteria in different concentrations of diazinon has been ini-tially an increasing trend and decreasing at the end. This results showed that Pseudomonas aeruginosa and Fla-vobacterium a good candidates for purification and eliminating of diazinon in contaminated soils." <
