Contamination of the environment with polycyclic
aromatic hydrocarbons is one of the major problems
facing the industrialized nations today. In this work,
Pseudomonas stutzeri
CET 930 was studied for the first
time as bioremediation agent for the degradation of effluents
containing phenanthrene, pyrene and benzanthracene,
both individually and mixed. The promising results of
degradation obtained at flask scale (92, 63 and 94 % in
7 days, respectively) marks the onset of the operation at
bench scale bioreactor. The overall biotransformation of
phenanthrene, pyrene and benzanthracene in batch operation
mode was 95, 78 and 82 % when present individually,
and 100, 98 and 100 % when carrying out the biological
process in cometabolic conditions, respectively. We have
demonstrated the great versatility of this strain for the
degradation of structurally different contaminants, such as
metal working fluids, polycyclic aromatic hydrocarbons or
insecticides such as chlorpyrifos, which makes it a suitable
candidate to be applied at industrial scale. In all cases, the
experimental data were successfully fitted to models, which
turned out to be valuable tools to classify the metabolites
involved in the biodegradation process as biomass-related.
Since a complete mineralization was pursued, the metabolic
pathways of the studied contaminants have been
proposed based on gas chromatography–mass spectrometry
data.
