title: Antioxidant enzymes are induced by phenol in the marine microalga Lingulodinium polyedrum.
abstract: Knowing the impacts of different anthropogenic activities on ecosystems promotes preservation of aquatic organisms. Aiming to facilitate the identification of polluted or contaminated areas, the study of microalga Lingulodinium polyedrum in phenol-containing medium comprises the determination of toxic and metabolic phenol effects, featuring a possible use of this microorganism as bioindicator for this pollutant. Marine microalga L. polyedrum exposure to phenol increases superoxide dismutase (SOD) and catalase (CAT) activities. The 20% and 50% inhibitory concentrations (IC20 and IC50) of cells exposed to phenol were 40 μmol L(-1) and 120 μmol L(-1), respectively. Phenol biodegradation by L. polyedrum was 0.02 μmol h(-1)cell(-1), and its biotransformation was catalyzed by glutathione S-transferase (GST), phenol hydroxylase and catechol 2,3-dihydroxygenase metabolic pathways. Phenol exposure produced the metabolites 2-hydroxymuconic semialdehyde acid, 1,2-dihydroxybenzene (catechol), and 2-oxo-4-pentenoic acid; also, it induced the activity of key antioxidant biomarker enzymes SOD and CAT by three folds compared to that in the controls. Further, phenol decreased the glutathione/oxidized glutathione ratio (GSH/GSSG), highlighting the effective glutathione oxidation in L. polyedrum. Overall, our results suggest that phenol alters microalga growth conditions and microalgae are sensitive bioindicators to pollution by phenol in marine environments.
authors.affiliation: Laboratório de Bioquímica e Biologia Molecular de Algas. Departamento de Bioquímica-Instituto de Química-Universidade de São Paulo Av. Prof. Lineu Prestes, 748-0970 São Paulo, SP, Brazil; Centro de Capacitação e Pesquisa em Meio Ambiente (CEPEMA-USP), Universidade de São Paulo. Rd. Cônego Domênico Rangoni, km 271, Cubatão, SP, Brazil. Electronic address: paula@cepema.usp.br.
authors.forename: P L G
authors.initials: PL
authors.lastname: Martins
authors.affiliation: Laboratório de Bioquímica e Biologia Molecular de Algas. Departamento de Bioquímica-Instituto de Química-Universidade de São Paulo Av. Prof. Lineu Prestes, 748-0970 São Paulo, SP, Brazil.
authors.forename: L G
authors.initials: LG
authors.lastname: Marques
authors.affiliation: Laboratório de Bioquímica e Biologia Molecular de Algas. Departamento de Bioquímica-Instituto de Química-Universidade de São Paulo Av. Prof. Lineu Prestes, 748-0970 São Paulo, SP, Brazil.
authors.forename: P
authors.initials: P
authors.lastname: Colepicolo
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D001673:Biodegradation, Environmental; D015415:Biomarkers / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D050557:Catechol 2,3-Dioxygenase / Q000378:metabolism; D002478:Cells, Cultured; D004141:Dinoflagellida / Q000187:drug effects* / Q000378:metabolism; D005229:Fatty Acids, Monounsaturated / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D006899:Mixed Function Oxygenases / Q000378:metabolism; D010084:Oxidation-Reduction; D010636:Phenols / Q000378:metabolism / Q000494:pharmacology*; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D000975:Antioxidants; D015415:Biomarkers; D005229:Fatty Acids, Monounsaturated; D010636:Phenols; C009785:4-pentenoic acid; D006899:Mixed Function Oxygenases; D002374:Catalase; D005979:Glutathione Peroxidase; D050557:Catechol 2,3-Dioxygenase; C022336:phenol 2-monooxygenase; D013482:Superoxide Dismutase; D005982:Glutathione Transferase
keywords: Environmental toxicology; Enzymatic activity; Organic pollutant; Phenol biotransformation