title: Effect of chromium on the fatty acid composition of two strains of Euglena gracilis.
abstract: The effect of hexavalent chromium on fatty acid composition was studied in two strains of Euglena gracilis; UTEX 753 (from the Culture Collection of Algae of Texas University, USA) and MAT (isolated from a highly polluted River). Both were grown in photoauxotrophic and photoheterotrophic conditions and exposed to two metal concentrations, one below and one above IC50. The high malondialdehyde (MDA) levels (3 to 7-fold) obtained with chromium concentration above IC50, suggested the existence of metal-induced lipid peroxidation. Total lipid content increased only with concentration below IC50, whereas it was inhibited by higher metal concentration. Photoheterotrophic control strains exhibited a significantly higher proportion of saturated and polyunsaturated fatty acids. Polyunsaturated acids were most affected by chromium, especially those related to chloroplast structures. Ultra-structure studies showed clear thylakoid disorganization in all treated cells. The results indicate that hexavalent chromium affects levels of fatty acids, especially those related to photosynthetic activity.
authors.affiliation: Departamento de Biodiversidad y Biología Experimental, Universidad de Buenos Aires, Pab. II, Ciudad Universitaria, 1428 Buenos Aires, Argentina. rocchetta@bg.fcen.uba.ar
authors.forename: Iara
authors.initials: I
authors.lastname: Rocchetta
authors.forename: Marcia
authors.initials: M
authors.lastname: Mazzuca
authors.forename: Visitación
authors.initials: V
authors.lastname: Conforti
authors.forename: Laura
authors.initials: L
authors.lastname: Ruiz
authors.forename: Vilma
authors.initials: V
authors.lastname: Balzaretti
authors.forename: María del Carmen
authors.initials: Mdel C
authors.lastname: Ríos de Molina
mesh_terms: D000818:Animals; D002274:Carcinogens, Environmental / Q000494:pharmacology; D002736:Chloroplasts / Q000737:chemistry; D002857:Chromium / Q000494:pharmacology*; D003470:Culture Media; D005056:Euglena gracilis / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D005227:Fatty Acids / Q000032:analysis*; D008055:Lipids / Q000032:analysis; D008315:Malondialdehyde / Q000032:analysis; D008854:Microscopy, Electron / Q000379:methods; D045483:Rivers / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000494:pharmacology*
chemical_list: D002274:Carcinogens, Environmental; D003470:Culture Media; D005227:Fatty Acids; D008055:Lipids; D014874:Water Pollutants, Chemical; D002857:Chromium; C074702:chromium hexavalent ion; D008315:Malondialdehyde