Toxicidad de los metales pesados sobre las microalgas: Efectos bioquímicos, fisiológicos y morfológicos

RODRÍGUEZ, M.C. ; ROCCHETTA, I; JUAREZ, A.B.; TOLIBIA, A.; CONFORTI, V.

Efecto de los cambios globales sobre biodiversidad

Programa CYTED

Año: 2008; p. 261 - 280

As a consequence of the increment in heavy metal aquatic pollution, several diagnostic and biomonitoring methods employing phytoplanktonic microalgae have been developed both at laboratory and field scale. Exposure of microalgae to heavy metals increases the level of oxidative stress, which is evidenced by the enhancing of lipid peroxidation and the alteration of photosystems. Concomitantly, several reactive oxygen species detoxifying mechanisms are switched on, including the production of metabolites such as ascorbate (vitamin C), reduced glutathione (GSH), a-tocopherol (vitamin E), carotenes and detoxifying enzymes such as catalase, ascorbate peroxidase, glutathione peroxidase, glutathione reductase and superoxide dismutase. The different mechanisms and responses for each algal species to heavy metal exposure allow the classification of species as: a) bioindicators of short time response (alarm biomonitoring), b) tolerant and c) resistant, conferring to these organisms a key role as diagnostic tools, in biomonitoring and in eventual biorremediation processes.