Degradation of spiked pyrene and non-pyrene hydrocarbons in soil microcosms by Pseudomonas species isolated from petroleum polluted soils

Abstract

The abilities of three Pseudomonads, Pseudomonas sp. strain LP1, Pseudomonas aeruginosa LP5 and P. aeruginosa LP6 to survive and enhance the degradation of pyrene and non-pyrene hydrocarbons in soil were tested in field-moist microcosms. All three organisms were able to survive and maintain high densities > × 107 in soil. In sterilized soils inoculated with bacterial isolates, 37.34%, 50.30%, and 42.21% were degraded by LP1, LP5, and LP6, respectively. The rates of pyrene degradation in soil microcosms were 0.046, 0.041, and 0.061 mg kg−1 h−1 for LP1, LP5, and LP6, respectively. A mixture of the three isolated degraded 7.73% was degraded in sterilized soil and 87.65% in native unsterilized soil (NS). The isolates also degraded non-pyrene hydrocarbon in the soils by more than 80%. The potentials these pseudomonads isolates for use as seed for bioremediation was successfully demonstrated.