Copper induced oxidative stress in culture of green microalgae

SCHIARITI, A.; JUÁREZ, A. B.; RODRÍGUEZ, M. C.

Buenos Aires

Congreso; IV Reunión anual de SETAC Latinoamérica; 2001

SETAC Latinoamérica

Sublethal copper exposure in cultures of microalge leads to a progressive massive oxidation of photosynthetic pigments, electron transport systems and, after severe expositions, to massive membrane disorganization. Oxidative stress after 48 hours’ incubation with copper concentrations of 50 and 100 mg . L-1 was evaluated in three green microalge strains (Coelastrum sphaericum, Chlorella kesslerii and Dictyosphaerium pulchellum) in presence and absence of an organic carbon source (glucose). Lipid peroxidation was detected and quantified by measuring malondialdelhyde (MDA) and other carbonyl by-products of lipid peroxidation which react with thiobarbituric acid (TBARS). TBARS results were expressed in relation to chlorophyll content per cell. Oxidative stress was always enhanced in cultures in presence of increasing copper concentrations but this effect was significantly reduced in the presence of an organic carbon source, even when pigment bleaching was evident with and without glucose.