title: Cadmium tolerance, cysteine and thiol peptide levels in wild type and chromium-tolerant strains of Scenedesmus acutus (Chlorophyceae).
abstract: Two strains of the unicellular green alga Scenedesmus acutus with different sensitivity to hexavalent chromium were compared for their tolerance of cadmium, by means of growth and recovery tests, and determination of cysteine, reduced glutathione and phytochelatin content, after short-term exposure to various cadmium concentrations (from 1.125 to 27 microM). Growth experiments showed that, after 7-day treatments with cadmium, the chromium-tolerant strain reached a significantly higher cell density and, after 24-h exposure to Cd, was able to resume growth significantly better than the wild type. Constitutive level of cysteine was higher in the chromium-tolerant strain, while glutathione levels were similar in the two strains. The higher content of cysteine and the maintenance of both reduced glutathione and phytochelatin high levels in the presence of cadmium, support the higher cadmium co-tolerance of the chromium-tolerant strain in comparison with the wild type one.
authors.affiliation: Department of Environmental Sciences, University of Parma, viale delle Scienze 33/A, 43100 Parma, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Torricelli
authors.forename: Gessica
authors.initials: G
authors.lastname: Gorbi
authors.forename: Barbara
authors.initials: B
authors.lastname: Pawlik-Skowronska
authors.forename: Luigi Sanità
authors.initials: LS
authors.lastname: Di Toppi
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Corradi
mesh_terms: D000704:Analysis of Variance; D002104:Cadmium / Q000633:toxicity*; D002851:Chromatography, High Pressure Liquid; D002857:Chromium / Q000633:toxicity; D003545:Cysteine / Q000378:metabolism*; D005978:Glutathione / Q000378:metabolism*; D008667:Metalloproteins / Q000378:metabolism*; D054811:Phytochelatins; D044444:Scenedesmus / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D013045:Species Specificity; D013997:Time Factors; D023382:Toxicity Tests, Acute
chemical_list: D008667:Metalloproteins; D002104:Cadmium; D002857:Chromium; D054811:Phytochelatins; D005978:Glutathione; D003545:Cysteine