Quinoline degradation by a bacterium isolated from deep subsurface sediments

Increasing evidence of chemical contamination in deep (>50 m) aquifers demonstrates the need to investigate organisms indigenous to, and understand microbiological transformations occurring within, these unique environments. A quinoline-degrading bacterium (facultative aerobe) was isolated from sediment 667 ft below the surface. The bacterium mineralizes quinoline at concentrations ranging from 0.002 to 165 μg/ml and degrades many other aromatic compounds. Genetic techniques showed that plasmid DNA was essential for the degradation of quinoline. These findings indicate that bacteria able to degrade homo- and heterocyclic compounds are present in some deep aquifers, and that the potential exists for the application of in situ bioremediation strategies in deep aquifers