title: Effect of chromium oxide (III) nanoparticles on the production of reactive oxygen species and photosystem II activity in the green alga Chlamydomonas reinhardtii.
abstract: With the growth of nanotechnology and widespread use of nanomaterials, there is an increasing risk of environmental contamination by nanomaterials. However, the potential implications of such environmental contamination are hard to evaluate since the toxicity of nanomaterials if often not well characterized. The objective of this study was to evaluate the toxicity of a chromium-based nanoparticle, Cr2O3-NP, used in a wide diversity of industrial processes and commercial products, on the unicellular green alga Chlamydomonas reinhardtii. The deleterious impacts of Cr2O3-NP were characterized using cell density measurements, production of reactive oxygen species (ROS), esterase enzymes activity, and photosystem II electron transport as indicators of toxicity. Cr2O3-NP exposure inhibited culture growth and significantly lowered cellular Chlorophyll a content. From cell density measurements, EC50 values of 2.05±0.20 and 1.35±0.06gL(-1) Cr2O3-NP were obtained after 24 and 72h of exposure, respectively. In addition, ROS levels were increased to 160.24±2.47% and 59.91±0.15% of the control value after 24 and 72h of exposition to 10gL(-1) Cr2O3-NP. At 24h of exposure, the esterase activity increased to 160.24% of control value, revealing a modification of the short-term metabolic response of algae to Cr2O3-NP exposure. In conclusion, the metabolism of C. reinhardtii was the most sensitive to Cr2O3-NP after 24h of treatment.
authors.affiliation: Department of Sanitary and Environmental Engineering, Federal University of Santa Catarina, Campus Universitário, CEP: 88040-970, Florianópolis, SC, Brazil.
authors.forename: Cristina Henning da
authors.initials: CHD
authors.lastname: Costa
authors.affiliation: School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ 85287-3005, United States.
authors.forename: François
authors.initials: F
authors.lastname: Perreault
authors.affiliation: Department of Chemistry, University of Quebec in Montréal, 2101, Jeanne Mance Street, Station Centre-Ville, Montréal, QC H2X 2J6, Canada.
authors.forename: Abdallah
authors.initials: A
authors.lastname: Oukarroum
authors.affiliation: Department of Sanitary and Environmental Engineering, Federal University of Santa Catarina, Campus Universitário, CEP: 88040-970, Florianópolis, SC, Brazil; Center of Marine Studies, Federal University of Parana, Beira-mar Avenue, 83255-976, Pontal do Parana, PR, Brazil.
authors.forename: Sílvia Pedroso
authors.initials: SP
authors.lastname: Melegari
authors.affiliation: Department of Chemistry, University of Quebec in Montréal, 2101, Jeanne Mance Street, Station Centre-Ville, Montréal, QC H2X 2J6, Canada.
authors.forename: Radovan
authors.initials: R
authors.lastname: Popovic
authors.affiliation: Department of Sanitary and Environmental Engineering, Federal University of Santa Catarina, Campus Universitário, CEP: 88040-970, Florianópolis, SC, Brazil. Electronic address: william.g.matias@ufsc.br.
authors.forename: William Gerson
authors.initials: WG
authors.lastname: Matias
mesh_terms: D016825:Chlamydomonas reinhardtii / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D017608:Chromium Compounds / Q000633:toxicity*; D004785:Environmental Pollutants / Q000633:toxicity*; D053768:Metal Nanoparticles / Q000633:toxicity*; D045332:Photosystem II Protein Complex / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D017608:Chromium Compounds; D004785:Environmental Pollutants; D045332:Photosystem II Protein Complex; D017382:Reactive Oxygen Species; C023600:chromic oxide
keywords: Cell viability; Chlamydomonas reinhardtii; Chromium oxide nanoparticles; Nanotoxicology; Oxidative stress