PROIMI   05436
PLANTA PILOTO DE PROCESOS INDUSTRIALES MICROBIOLOGICOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Growth of Actinobacteria with alfa-, beta and delta- Hexachlorocyclohexane isomers as the only carbon source.
Autor/es:
CUOZZO S.A.; PONCE, J.; BENIMELI CLAUDIA S.; AMOROSO MARÍA J.
Lugar:
Puerto Vallarta
Reunión:
Simposio; 16th International Symposium on the Biology of Actinomycetes; 2011
Institución organizadora:
Sociedad Internacional de Actinomycetes
Resumen:
 Hexachlorocyclohexane (HCH)  is a highly toxic and persistent organochloride pesticide that has caused serious environmental problems since it began to be produced at the beginning of the 1940s. During the synthesis process of HCH different isomers are produced. All HCH isomers have the same molecular formula 1,2,3,4,5,6-HCH, but are differentiated by variations in the axial-equatorial positions of the molecules of chlorine around a ring of 6 carbons. Of all the isomers, only  ¥ã-HCH (lindane) possesses insecticidal activity; however the other isomers are still toxic for humans.   For this  reason we have focused on the selection of actinobacteria able to growth in HCH isomers. Five actinobacteria strains, previously isolated from pesticide contaminated soils,  and the reference strain  Streptomyces coelicolor A3 (2) were selected. All strains were grown in Minimal Medium (MM), supplemented with each HCH isomer (¥á, ¥â y ¥ä−HCH). They were added aseptically to the autoclaved medium at a final concentration of 1.66 mg L-1. These strains were also grown in presence of glucose as the only carbon source. All cultures were incubated on a rotatory shaker (100 rpm) at 30 ¨¬C, for 96 h. The biomass produced was measured by dry weight, washing the pellets with 25mMTris-EDTA buffer (pH 8.0) and drying to constant weight at 105 ¨¬C. It was observed that actinobacterias: Streptomyces sp. A2, A8 and M7 were able to grow 2.5, 1.5 or 1.4 times more than  in the presence of ¥á-HCH as the only carbon source. When ¥â-HCH was added, Streptomyces sp. A2, and M7 were capable to grow 1.5 times more than in control cultures. However in the presence of  ¥ä-HCH all the strains showed similar growth  as with glucose.  Therefore the best obtained performances were with A2 and A8 strains. These are the first obtained results, where actinobacteria can grow in presence of HCH-isomers. It is important to notice that  ¥â-HCH, is the most recalcitrant. For this reason actinobacteria could be considered as promising strains for HCH isomers degradation from contaminated areas.