RESUMO
Much effort has been given at the present to the use of microorganisms in the decontamination of organophosphorus pesticides [OP's]. Here we studied the role of repetitive exposure to low doses of OP and the influence of glucose as energy source on the activities of E. coli strains isolated from local environment for biodetoxification of OP. Results indicated that adapted E. coli strains were superior in their OP detoxification activity than wild. An isolated strain of E. coli from water samples [Wx2] showed the maximum activity among other strains for paraoxon biodetoxification. Adding glucose to the wild and adapted strains did not enhance their OP's biodegradation activities. Bioreactor column for OP's detoxification was build using promising adapted strain. The bioreactor achieved 57.49% biodegradation efficiency of the applied 0.1 mM paraoxon concentration. The efficiency of the bioreactor was maintained up to 30 days from its construction. The results suggest that adaptation of this strain of bacteria by exposure to the concentrations of the organophosphate insecticides can enhance its efficiency in degradation of these compounds that may introduced an efficient, cheap and environmental friendly technique for pollutants decontamination