title: Uptake and biotransformation of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) in four marine microalgae species.
abstract: Hydroxylated- and methoxylated- polybrominated diphenyl ethers (OH-PBDEs and MeO-PBDEs) are more toxic than PBDEs and occur widely in the marine environment, and yet their origins remain controversial. In this study, four species of microalgae (Isochrysis galbana, Prorocentrum minimum, Skeletonema grethae and Thalassiosira pseudonana) were exposed to BDE-47, which is synthetic and is the predominant congener of PBDEs in the environment. By chemical analysis after incubation of 2 to 6 days, the efficiency of uptake of BDE-47 and, more importantly, the potential of undergoing biotransformation to form OH-PBDEs and MeO-PBDEs by the microalgae were investigated. Growth rates of these axenic microalgae were not affected upon exposure to environmentally relevant concentrations (0.2-20 μg BDE-47 L-1), and accumulation ranged from 0.772 ± 0.092 μg BDE-47 g-1lipid to 215 ± 54 μg BDE-47 g-1lipid within 2 days. Debromination of BDE-47 and formation of BDE-28 occurred in all microalgae species (0.01 to 0.87%), but biotransformation to OH-PBDEs was only found in I. galbana upon exposure to extremely high concentration. The results of this study showed that biotransformation of microalgae species is unlikely an explanation for the OH-PBDEs and MeO-PBDEs found in the marine environment.
authors.affiliation: Department of Biology, Hong Kong Baptist University, Hong Kong.|School of Biological Sciences, University of Hong Kong, Hong Kong.
authors.forename: Beverly H K
authors.initials: BH
authors.lastname: Po
authors.affiliation: Department of Biology and Chemistry, City University of Hong Kong, Hong Kong.
authors.forename: Ka-Lok
authors.initials: KL
authors.lastname: Ho
authors.affiliation: Department of Biology and Chemistry, City University of Hong Kong, Hong Kong.
authors.forename: Michael H W
authors.initials: MH
authors.lastname: Lam
authors.affiliation: School of Biological Sciences, University of Hong Kong, Hong Kong.|Department of Biology and Chemistry, City University of Hong Kong, Hong Kong.|Toxicology Centre, University of Saskatchewan, Saskatoon, SK S7N 5B3, Canada.
authors.forename: John P
authors.initials: JP
authors.lastname: Giesy
authors.affiliation: Department of Biology, Hong Kong Baptist University, Hong Kong.
authors.forename: Jill M Y
authors.initials: JM
authors.lastname: Chiu
mesh_terms: D001692:Biological Transport; D001711:Biotransformation; D004784:Environmental Monitoring / Q000379:methods*; D055768:Halogenated Diphenyl Ethers / Q000378:metabolism* / Q000493:pharmacokinetics; D006900:Hydroxylation; D058086:Microalgae / Q000145:classification / Q000378:metabolism*; D012623:Seawater; D013045:Species Specificity; D014874:Water Pollutants, Chemical / Q000378:metabolism* / Q000493:pharmacokinetics
chemical_list: D055768:Halogenated Diphenyl Ethers; D014874:Water Pollutants, Chemical; C511295:2,2',4,4'-tetrabromodiphenyl ether