INVESTIGADORES
ROCCHETTA iara
congresos y reuniones científicas
Título:
Response of Superoxide Dismutase and Catalase to different stress conditions in Euglena gracilis
Autor/es:
ROCCHETTA, I. RUIZ, L. CONFORTI, V. AND M. C. RÍOS.
Lugar:
Almeria, España
Reunión:
Congreso; 1º Congress of the International for Society Applied Phycology; 2002
Institución organizadora:
International Society for Applied Phycology
Resumen:
   Euglena gracilis showed metabolic and morphological changes when was exposed to different stress conditions including toxic metals. We studied the role of antioxidant enzymes (superoxide dismutase (SOD) and peroxydases); and the lipidic peroxidation by thiobarbituric acid reactive substances (TBARS) and total lipids during adverse conditions. Two strains of Euglena gracilis, one isolated from a highly polluted river (MAT) and the other come from a culture collection (UTEX) was used for this study. Both strains were grown in different culture media (Buetow, Cramers & Myers and EGM) and were exposed to different concentrations of hexavalent chromium during 96 hs.    All treated cells exhibited high activity of SOD showing a greater production the UTEX one, while catalase-like levels decreased.    TBARS levels showed an increased in the amount measured while the total lipids diminished respect to the chromium concentrations used. These results would show  increased antioxidant defenses are not enough to avoid a lipidic peroxidation in treated cells.    Non-treated cells showed differences according to the culture media used. Catalase-like activity showed a negative relation respect to the organic matter content and the pH decrease, showing less activity in the EGM medium. Beetwen strains, UTEX  showed a higher enzyme activity.    We conclude that antioxidant enzymes activity depend on the culture conditions and the type of strain, therefore their protective role to oxidative stress would only be partially effective.