Enrichment culture experiments employing soil and water samples obtained fr
om petroleum-contaminated environments succeeded in the isolation of a pure
culture possessing the ability to utilize quinoline as a sole nitrogen sou
rce but did not utilize quinoline as a carbon source. This culture was iden
tified as Pseudomonas ayucida based on a partial 16S rRNA gene sequence, an
d the strain was given the designation IGTN9m. Examination of metabolites u
sing thin-layer chromatography and gas chromatography-mass spectrometry sug
gests that P. ayucida IGTN9m converts quinoline to 2-quinolinone and subseq
uently to 8-hydroxycoumerin, Resting cells of P. ayucida IGTN9m were shown
to be capable of selectively removing about 68% of quinoline from shale oil
in a 16-h treatment time. These results suggest that P. ayucida IGTN9m may
be useful in petroleum biorefining for the selective removal of organicall
y bound nitrogen from petroleum.