title: Detoxification of 2,4-dichlorophenol by the marine microalga Tetraselmis marina.
abstract: Xenobiotic chlorinated phenols have been found in fresh and marine waters and are toxic to many aquatic organisms. Metabolism of 2,4-dichlorophenol (2,4-DCP) in the marine microalga Tetraselmis marina was studied. The microalga removed more than 1mM of 2,4-DCP in a 2l photobioreactor over a 6 day period. Two metabolites, more polar than 2,4-DCP, were detected in the growth medium by reverse phase HPLC and their concentrations increased at the expense of 2,4-DCP. The metabolites were isolated by a C8 HPLC column and identified as 2,4-dichlorophenyl-beta-d-glucopyranoside (DCPG) and 2,4-dichlorophenyl-beta-d-(6-O-malonyl)-glucopyranoside (DCPGM) by electrospray ionization-mass spectrometric analysis in a negative ion mode. The molecular structures of 2,4-DCPG and 2,4-CPGM were further confirmed by enzymatic and alkaline hydrolyses. Thus, it was concluded that the major pathway of 2,4-DCP metabolism in T. marina involves an initial conjugation of 2,4-DCP to glucose to form 2,4-dichlorophenyl-beta-d-glucopyranoside, followed by acylation of the glucoconjugate to form 2,4-dichlorophenyl-beta-d-(6-O-malonyl)-glucopyranoside. The microalga ability to detoxify dichlorophenol congeners other than 2,4-DCP was also investigated. This work provides the first evidence that microalgae can use a combined glucosyl and malonyl transfer to detoxify xenobiotics such as dichlorophenols.
authors.affiliation: Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens, 9, Iroon Polytechniou Str, Zografou Campus, Athens 15780, Greece.
authors.forename: Dimitris
authors.initials: D
authors.lastname: Petroutsos
authors.forename: Petros
authors.initials: P
authors.lastname: Katapodis
authors.forename: Martina
authors.initials: M
authors.lastname: Samiotaki
authors.forename: George
authors.initials: G
authors.lastname: Panayotou
authors.forename: Dimitris
authors.initials: D
authors.lastname: Kekos
mesh_terms: D019149:Bioreactors; D002733:Chlorophenols / Q000737:chemistry / Q000378:metabolism* / Q000633:toxicity; D000460:Chlorophyta / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D015394:Molecular Structure; D013237:Stereoisomerism; D013997:Time Factors; D018675:Toxicity Tests; D014874:Water Pollutants, Chemical / Q000378:metabolism* / Q000633:toxicity; D015262:Xenobiotics / Q000378:metabolism
chemical_list: D002733:Chlorophenols; D014874:Water Pollutants, Chemical; D015262:Xenobiotics; C004762:2,4-dichlorophenol