IIB   20738
INSTITUTO DE INVESTIGACIONES BIOLOGICAS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Phenanthrene degradation by halophilic microorganisms isolated from La Pampa saltern ponds
Autor/es:
DI MEGLIO, L.; BUSALMEN, J. P.; NERCESSIAN, D.
Lugar:
Mar del Plata
Reunión:
Congreso; X Congreso de la Sociedad Argentina de Microbiología General (SAMIGE); 2014
Institución organizadora:
Sociedad de Microbiología General
Resumen:
Phenanthrene degradation by halophilic microorganisms isolated from La Pampa saltern ponds. Degradación de fenantreno por microorganismos halofílicos aislados de salinas pampeanas. Di Meglio LG1, Busalmen JP2 and Nercessian D1 1 Instituto de Investigaciones Biológicas, UNMdP-CONICET, Mar del Plata, Argentina 2 Lab. de Bioelectroquímica, Div. Electroquímica y Corrosión INTEMA-CONICET, Mar del Plata, Argentina leonardo_dimeglio@yahoo.com.ar Polycyclic Aromatic Hydrocarbons (PHAs) are compounds with two or more fused aromatic rings that are highly toxic because of their mutagenic and carcinogenic effects on living organisms. Bioremediation technology employs microorganisms which are able to metabolize toxic compounds and transform them into harmless ones. In this direction, much has been studied about bacterial remediation, but the knowledge about metabolic pathways and enzymes involved in hydrocarbon degradation in hypersaline environments is scarce. One important source of PHAs pollution is waste water of oil production process, which is indeed generated in large amount. Because of its high saline content, microorganisms conventionally employed in PHAs remediation cannot be effective in biological treatment of this waste water, which took researchers to consider extremophilic microorganisms, as halophilic archaea. We isolated and identified nine microorganisms (seven Archaea and two Bacteria) of La Colorada Grande, Salitral Negro and Guatraché saltern ponds located in La Pampa province. They were tested, along with other halophilic microorganisms and consortia, to evaluate their hydrocarbon degrading capacity. For this, degradation assays were performed in liquid medium under low oxygen concentration in the presence of 0.02% phenanthrene, for four weeks. Degradation products and the remaining phenanthrene were extracted from the extracellular medium with ethyl acetate and analyzed by High Resolution Liquid Chromatography (HPLC). Chromatograms evidenced complete phenantrene degradation by eight of the tested strains, to different byproducts, while an additional strain showed only partial degradation (about 70%). Degradation by halophilic consortia was greater than 50%. Three of the more effective microorganisms (Halobacterium piscisalsi, Haloarcula argentinensis and Salicola sp.) were selected for further analysisof the degradation pathways by gas chromatography, which allowed the assessment of both aromatic and aliphatic hydrocarbons and the identification of the byproducts. Supported by CONICET, ANPCyT and UNMdP.