title: Oxidative stress and antioxidant defenses in two green microalgae exposed to copper.
abstract: The aim of this work was to assess the effects of 1 week copper exposure (6.2, 108, 210 and 414microM) on Scenedesmus vacuolatus and Chlorella kessleri. The strains showed different susceptibility to copper. Copper content was determined in both strains by total X-ray reflection fluorescence analysis (TXRF). In S. vacuolatus, the increase of medium copper concentration induced an augmentation of protein and MDA content, and a significant decrease in the chlorophyll a/chlorophyll b ratio. S. vacuolatus showed a significant increase of catalase activity in 210 and 414microM of copper, and a significant increment of SOD activity and GSH content only in 414microM of copper. On the contrary, C. kessleri did not show significant differences in these parameters between 6.2 and 108microM of copper. Increased copper in the environment evokes oxidative stress and an increase in the antioxidant defenses of S. vacuolatus.
authors.affiliation: Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pab. II, Ciudad Universitaria, Ciudad Autónoma de Buenos Aires, CP 1428, Buenos Aires, Argentina. sabatini@bg.fcen.uba.ar
authors.forename: Sebastián E
authors.initials: SE
authors.lastname: Sabatini
authors.forename: Angela B
authors.initials: AB
authors.lastname: Juárez
authors.forename: Maria R
authors.initials: MR
authors.lastname: Eppis
authors.forename: Laura
authors.initials: L
authors.lastname: Bianchi
authors.forename: Carlos M
authors.initials: CM
authors.lastname: Luquet
authors.forename: María del Carmen
authors.initials: Mdel C
authors.lastname: Ríos de Molina
mesh_terms: D020418:Algal Proteins / Q000096:biosynthesis; D000975:Antioxidants / Q000378:metabolism*; D002374:Catalase / Q000096:biosynthesis; D002614:Chelating Agents / Q000032:analysis / Q000378:metabolism; D002708:Chlorella / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D002734:Chlorophyll / Q000096:biosynthesis; D003300:Copper / Q000032:analysis / Q000378:metabolism / Q000633:toxicity*; D004492:Edetic Acid / Q000032:analysis / Q000378:metabolism; D005978:Glutathione / Q000096:biosynthesis; D015227:Lipid Peroxidation / Q000187:drug effects; D008315:Malondialdehyde / Q000032:analysis / Q000378:metabolism; D015233:Models, Statistical; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000187:drug effects*; D044444:Scenedesmus / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D013052:Spectrometry, X-Ray Emission; D013482:Superoxide Dismutase / Q000096:biosynthesis
chemical_list: D020418:Algal Proteins; D000975:Antioxidants; D002614:Chelating Agents; D002734:Chlorophyll; D008315:Malondialdehyde; D003300:Copper; D004492:Edetic Acid; D002374:Catalase; D013482:Superoxide Dismutase; D005978:Glutathione