OLIVERA nelda Lila
congresos y reuniones científicas
LAS degrading Vibrio sp. from marine water of Argentina
SILVIA PERESSUTTI; NELDA OLIVERA; HÉCTOR ALVAREZ; PAOLA BABAY; MARCELA COSTAGLIOLA
Congreso; VIBRIO2007 Congress; 2007
Linear alkylbenzene sulfonate (LAS) is the major synthetic surfactant which can cause serious environmental pollution with toxic effects on living organisms. Even though its biodegradation process has been studied for a variety of ecosystems, there is no information available on LAS degrading microorganisms in the Río de la Plata brackish and adjacent marine waters in Argentina. The aim of this work was to select and identify autochthonous LAS degrading microorganisms obtained from these environments and to analyze their effectiveness on LAS degradation. Collected water samples were used for LAS degraders enrichment. Isolates were identified by biochemical and molecular techniques. Biodegradation was established measuring LAS disappearance by HPLC. A four-member bacterial consortium capable of using LAS as the sole carbon source was isolated and identified as Aeromonas, Pseudomonas and Vibrio genera. The Vibrio genus strain yielded similarity values above 99 % when the 16S rDNA sequences were compared with V. campbelli, V. natriegens, V. alginolyticus, and V. parahaemolyticus. By means of biochemical tests, this isolate was identified as V. parahaemolyticus. Nearly 86% of LAS degradation was achieved by the consortium assaying a fixed LAS concentration of 20 mg liter-1. Single strains yielded lower LAS decrease than the consortium. Vibrio sp. strain accounted for 21% of LAS degradation, and led to higher degradation of shorter-chain LAS homologues. The strains making up the consortium complemented each other regarding their biodegradation activity. In addition, approximately 100% of LAS was transformed by the consortium when its medium concentration reached 10 mg liter-1. To conclude, this is the first report on LAS degrading strain belonging to Vibrio genus. The consortium obtained a complete LAS degradation, suggesting its good potential for LAS disposal from these polluted ecosystems.