Evaluation of diazinon pesticide biodegradation by isolated indigenous bacteria from contaminated soil

Pesticides have been developed as powerful tools that apply for population feeding needs, all over the world. Pesticides’ overuse has become a serious issue about the environment. Among pesticides, diazinon is one of the organophosphorus inceticides that is used to control many different kinds of pests. There are a lot of researches about the toxicity effects of pesticides on the environment. However, one of the strategies to remove them from different environments is using degradation bacteria.
For screening vernacular bacterium that are able to degrade the pesticide the sampling has been done from different soils of agriculture and industrial places, and the mineral salt medium was used for extvation of bacteria. After enrichment of samples in the mineral salt media, the isolation was done in the soild medium and 10 different sterains were based on morphology characters extracted and were identified to species level. The concentration of diazinon in the presence of bacteria was determined as a high performance liquid chromatography (HPLC).
Among diazinon degradetion isolates S1 and S2 reduced the concentration of diazinon from 50 mg.l to 3.18 mg.l and 5.21 mg.l after 15 days, respectivly. The results indicated that S1 and S2 have higher efficiency to decreasing the amount of pesticide. Based on growing bacteria in the poor medium it’s shown that bacteria used diazinon as an energy source. Results indicated that amplification and sequencing of 16S rDNA of S1 and S2 isolated have the highest similarity with Paenibacillus and Pseudomonas, respectively.
Discussion and Results of this study revealed that degradation bacteria of diazinon exist in the places that used this insecticide and in the waste of industrial zone. It is expected that using these bacteria and biological resuscitation, it is possible to reduce some environmental hazardus issues of diazinon and also field application and determining the best formulation for bioramidation are essential in the future