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International Journal of Environment Science and Technology
Center for Environment and Energy Research and Studies (CEERS)
ISSN: 1735-1472 EISSN: 1735-1472
Vol. 12, No. 4, 2015, pp. 1353-1362
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Bioline Code: st15125
Full paper language: English
Document type: Research Article
Document available free of charge
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International Journal of Environment Science and Technology, Vol. 12, No. 4, 2015, pp. 1353-1362
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Isolation and characterization of an aerobic bacterial consortium able to degrade roxarsone
Guzmá n-Fierro, V.G.; Moraga, R.; León, C.G.; Campos, V.I.; Smith, C. & Mondaca, M.A.
Abstract
Roxarsone is an organoarsenical compound
used as food additive in the poultry industry. Roxarsone
has the potential risk to contaminate the environment,
mainly by the use of poultry industry manure as fertilizer,
releasing inorganic arsenic to the soil and water. The aim
of this work was to isolate and characterize a bacterial
consortium capable to degrade roxarsone under aerobic
conditions. A bacterial consortium was cultured from a soil
sample obtained from a field fertilized with poultry litter
containing roxarsone. The consortium was cultured in the
presence or absence of roxarsone. Roxarsone degradation
and growth kinetics were determined by incubation of the
bacterial consortium in the presence of roxarsone at room
temperature and under aerobiosis. Both consortiums were
characterized molecularly by denaturing gradient gel
electrophoresis analysis and metabolically using Biolog
Ecoplates. Inorganic arsenic was assessed by precipitation
with silver nitrate. The consortium was also analyzed by
scanning electron microscopy. The results showed that
growth rate of the bacterial consortium was 1.4-fold higher
in presence of roxarsone and 81.04 % of the roxarsone
was transformed after 7 days of incubation. Molecular
characterization revealed the presence of different bacterial
groups, being alphaproteobacteria and firmicutes the
groups that showed the highest count in both consortiums.
The metabolic profile of the consortium did not change in
the presence of roxarsone, but it showed a greater ability to
oxidize amines, suggesting production of functional amines
to decrease the stability of the aromatic ring resonance
energy, the principal problem associated with aromatic
compounds degradation.
Keywords
Roxarsone; Arsenic; Biotransformation; Soil; Bacterial consortium
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