Biodegradation of organophosphorus compounds by extremely halophilic bacteria

摘要

Biodegradation, a biological reduction in toxicity of chemicals, is a promising technique for decontaminating our environment. Recent studies show the potential of Halobacteria in reducing waste disposal through their capacity of biodegrading organophosphorus compounds. This research dealt with new halobacterial species, PR #3 and PR #5, recently discovered in Puerto Rico. Halobacteria belong to the order Halobacteriales of the domain Archae and their dominant feature is their requirement for high concentration of salt. PR #3 and PR #5 were evaluated to assess their potential for degrading two commercial pesticides, Parathion and Paraoxon, as part of their metabolic process. Microbial growth was determined in the presence or absence of the pesticides at different concentrations utilizing an UV-Vis spectrophotometer. Crude cell extracts from these isolates were used to perform different enzymatic assays using $sp{31}$P Nuclear Magnetic Resonance, fluoride ion-selective electrode and UV-Vis spectrophotometer. Results showed microbial growth with or without either pesticide at three concentrations. The bacteria also showed some biodegrading capacity through the enzymatic assays performed with both pesticides tested.