INVESTIGADORES
DAVILA COSTA Jose Sebastian
congresos y reuniones científicas
Título:
Bioremediation of a pesticides mixture by a Streptomyces consortium in different systems
Autor/es:
ENZO RAIMONDO; MARÍA SOLEDAD FUENTES; JULIANA SAEZ; JOSÉ DÁVILA COSTA; SERGIO CUOZZO; CLAUDIA BENIMELI
Reunión:
Simposio; XVII International Symposium on the Biology of Actinomycetes; 2014
Resumen:
Pesticides are usually applied simultaneously or
one after another for crop protection, and their application often leads to a
combined contamination of soils by these residues. Furthermore, it is important
to characterize these mixtures due to their persistence, composition and
geographical distribution. Organochlorine pesticides are persistent pollutants,
and currently are still ubiquitous in the environment. The bioremediation
offers the possibility to remove these toxic pollutants by using biological
activity and the use of actinobacteria consortia is an attractive approach
because of their ability to degrade pesticides and to increase the metabolic
pathways to achieve it.
The aim of this work was to study the ability of
an actinobacteria consortium to remove an organochlorine pesticides mixture
(lindane, chlordane and methoxychlor) under control laboratory conditions, in
slurry and soil systems.
The consortium Streptomyces sp. A2, A5,
A11 and M7, previously selected for its ability to remove lindane, were
pre-cultivated 72h as pure cultures in trypticase soy broth. Then these strains
were inoculated as a defined consortium (2 g Kg-1 of soil or
slurry), in sterile and non-sterile soil and in sterile slurry systems, and
incubated for 16 days at 30 °C. The soil used was classified as silty clay
loam. All tests were carried out in presence of the organoclorine pesticides
mixture (1.66 mg Kg-1 each one). Respectively controls were carried
out. Residual pesticides concentrations were measured by gas chromatography.
The effect of the kind of system used for the mixture removal was analyzed by
the main effect plot.
The removal of the mixture was different for each
pesticide and among the different systems. In the case of sterile soil the
removal percentages were 38.9% for methoxychlor, 31.2% for lindane and 22.5%
for chlordane. In non-sterile soil the removal percentages were 21% and 25.4%
for methoxychlor and lindane. For the slurry system the removal percentages
were 10.2% and 35.9% for methoxychlor and lindane respectively. Chlordane
removal was no detected in both systems.
The main effect plots analysis showed that the kind
of system has a significant effect on the removal of methoxychlor and chlordane,
showing statistically significant differences (P <0.05) in the
different matrix; however this is not true for the case of lindane (P >
0.05).
The type of systems used in the bioremediation
process has a significant effect on the removal of the organochlorine
pesticides mixture. The actinobacteria consortium has the ability to remove
organoclorine pesticides in soil and slurry systems and could be a promising tool
for ex-situ or in-situ bioremediation of this toxic compounds
mixture.