title: Photosynthetic activity and protein overexpression found in Cr(III)-tolerant cells of the green algae Dictyosphaerium chlorelloides.
abstract: Chromium is an important constituent in effluents obtained from chromium plating industries. Due to the highly toxic nature of Cr(VI), attention has been shifted to less hazardous Cr(III) electroplating processes. This study evaluated aquatic toxicity of Cr(III)-containing laboratory samples representative of effluents from chromium electroplating industries, on the photosynthetic activity exhibited by both Cr(III)-sensitive (Dc1M(wt)) and tolerant (Dc1M(Cr(III)R30)) Dictyosphaerium chlorelloides strains. Additionally, selected de novo-determined peptide sequences, obtained from Dc1M(Cr(III)R30), have been analyzed to evidence the possible Cr(III) toxic mechanism involved in the resistance of these cells to high Cr(III) levels in aquatic environments. Dc1M(Cr(III)R30) strain exhibited a gross photosynthetic balance of about five times lower than that exhibited by Dc1M(wt) strain, demonstrating that Dc1M(Cr(III)R30) has a photosynthetic yield significantly lower than Dc1M(wt). SDS-PAGE of Dc1M(Cr(III)R30) samples showed the presence of at least two protein bands (23.05 and 153.46 KDa, respectively) absent in wild-type strain samples. Although it has achieved a low coincidence between the lower molecular weight band and a GTPase identified from genome of the green alga Chlamydomonas reinhardtii, none of de novo peptide sequences obtained showed a significant MS-BLAST score, so that further studies will be required.
authors.affiliation: Department of Toxicology and Pharmacology, Faculty of Veterinary Medicine, Universidad Complutense de Madrid, Avda. Puerta de Hierro s/n, 28040 Madrid, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Pereira
authors.affiliation: School of Chemistry-Pharmacobiology, Michoacana de San Nicolás de Hidalgo University, 43 Santiago Tapia St., 58000 Morelia, Michoacán, Mexico.
authors.forename: C M
authors.initials: CM
authors.lastname: Bartolomé
authors.affiliation: Department of Toxicology and Pharmacology, Faculty of Veterinary Medicine, Universidad Complutense de Madrid, Avda. Puerta de Hierro s/n, 28040 Madrid, Spain. Electronic address: fortun@ucm.es.
authors.forename: S
authors.initials: S
authors.lastname: Sánchez-Fortún
mesh_terms: D000595:Amino Acid Sequence; D016825:Chlamydomonas reinhardtii / Q000187:drug effects; D000460:Chlorophyta / Q000187:drug effects* / Q000235:genetics / Q000502:physiology*; D002857:Chromium / Q000633:toxicity*; D004351:Drug Resistance / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D004595:Electroplating; D020558:GTP Phosphohydrolases / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D018745:Genome, Plant; D008969:Molecular Sequence Data; D010788:Photosynthesis / Q000187:drug effects*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D040901:Proteomics; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000633:toxicity*
chemical_list: D010940:Plant Proteins; D014874:Water Pollutants, Chemical; D002857:Chromium; D020558:GTP Phosphohydrolases
keywords: Cr(III); Dictyosphaerium chlorelloides; Environmental adaptation; MALDI-TOF/TOF MS; Photosynthetic activity