OLIVERA nelda Lila
congresos y reuniones científicas
Isolation of linear alkylbenzene sulfonate (LAS)-degrading Aeromonas strains from the Río de la Plata estuary
SILVIA PERESSUTTI; NELDA LILA OLIVERA; PAOLA BABAY; MARCELA COSTAGLIOLA; HECTOR ALVAREZ
Simposio; 14th International Biodeterioration & Biodegradation Symposium; 2008
International Biodeterioration & Bidegradation Society-FEMS- University of Messina
Coastal ecosystems receive large quantities of surfactants as linear alkylbenzene sulfonate (LAS) from urban and industrial wastewater. LAS can cause serious environmental pollution with toxic effects on living organisms, producing physical and physiological alterations in fishes, crustaceans and phytoplankton. The purpose of this work was to identify autochthonous LAS degrading microorganisms isolated from the Río de la Plata estuary and to analyze their effectiveness on degradation of commercial LAS. Two bacterial strains belonging to Aeromonas caviae species were isolated from water samples. They were able to mineralize (CO2 releasing) and desulfonate LAS, degrading 44 and 61% of LAS (20 mg liter-1) after 28 days. Degradation rates could be enhanced when the Aeromonas strains were co-cultivated with other less efficient LAS-degrading bacteria, such as Pseudomonas alcaliphila, Vibrio sp. and Rhodococcus opacus, which individually degraded 35, 21 and 7% of LAS, respectively. In addition, the presence of co-substrates such as hexadecane in the culture media improved LAS biodegradation. Results suggested that some of the strains used in the consortia may be able to utilize the intermediary oxidation products of the other microorganisms. We concluded that LAS-degrading Aeromonas strains isolated in this study, with high effectiveness on LAS biodegradation, represents a useful tool for LAS depletion from polluted ecosystems, such as Río de la Plata (Argentina), where other microorganisms and substrates are available for co-oxidation.