Effects of urban discharge on lipid and fatty acid composition of Diplodon chilensis.

YUSSEPPONE, M.S., ROCCHETTA, I., PASQUEVISCH, M.Y., HERAS, H., LUQUET, C.M. & RÍOS DE MOLINA, M.C.

Congreso; XLVII Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular.; 2011

The mussel Diplodon chilensis is abundant in lakes and rivers of Patagonia and is considered as a potential bioremediation tool for reducing coliform bacteria in domiciliary wells. We evaluated changes in lipid and fatty acid composition, by TLC and GC, in mussels exposed to control and urban discharge polluted sites. Oxidative stress parameters (antioxidant enzymes, GSH, lipid and protein oxidation) as well as glycogen and lipofuxin contents were determined. The neutral/polar lipid ratio was higher in organisms sampled at the polluted area due to an increase in DAG and TAG and a decrease in PE. Polar lipids were the most affected, with increased saturated FA (C18:0) and decreased unsaturated FA, n3 and n6 (C16:1n7, C20:4n6, C21:5n3, C22:3n6) contents. Bivalves from the polluted area showed higher lipid oxidation, lipofuxins and GSH levels, and lower glycogen content. No changes were observed in antioxidant enzyme activities. These results demonstrate that chronic exposure of D. chilensis to urban effluents produces an increase in GSH level, which is not enough to counteract the oxidative damage to lipids, especially to the polar ones and their PUFA. The latter effect suggests changes in membrane permeability. The levels of lipid storage are probably maintained at the expense of glycogen consumption.