title: Cellular responses, biodegradation and bioaccumulation of endocrine disrupting chemicals in marine diatom Navicula incerta.
abstract: The cellular responses, biodegradation and bioaccumulation of four endocrine disrupting chemicals, including nonylphenols (NPs), bisphenol A (BPA), 17alpha-ethynylestradiol (EE2), and estradiol (E2), in the marine diatom Navicula incerta, were investigated through the 96-h exposure test. The 50% effective concentration (EC(50)) values in the algal growth inhibition test for NPs, BPA, EE2 and E2 were 0.20mgL(-1), 3.73mgL(-1), 3.21mgL(-1) and >10mgL(-1), respectively. With the increase of test concentrations, the cellular contents of polysaccharides and protein were reduced but the lipid content was increased, while the levels of chlorophyll a and total chlorophyll c were not affected by target EDCs. The activities of superoxidase dismutase and glutathione-S-transferase were stimulated by EDCs. The activities of peroxide dismutase were inhibited by NPs, BPA, and EE2, but were enhanced by E2. The bioaccumulation and biodegradation of target EDCs were inhibited with the increasing exposure concentrations. Nevertheless, the toxic and inhibitory effects of these EDCs on the diatom at their environmental relevant concentrations were relatively low. At the environmental relevant concentration (0.001mgL(-1)), 20.69% of NPs, 37.78% of BPA, 31.26% of EE2 and 52.26% of E2 were removed from the seawater in 96h via biodegradation, and the respective 96-h bioconcentration factor (BCF) values were 2077, 261, 470, and 39. These results showed that among the four target EDCs, NPs would be most problematic as reflecting by their low biodegradation and high BCF in the diatom, suggesting that the NPs would accumulate within the algal cell and pose threats to organisms at higher tropic levels, especially the larvae feeding on the diatom.
authors.affiliation: Department of Environmental Science and Engineering, Tsinghua University, Beijing, PR China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.forename: Yuntao
authors.initials: Y
authors.lastname: Guan
authors.forename: Qingtan
authors.initials: Q
authors.lastname: Gao
authors.forename: Nora Fung Yee
authors.initials: NF
authors.lastname: Tam
authors.forename: Wanpeng
authors.initials: W
authors.lastname: Zhu
mesh_terms: D001559:Benzhydryl Compounds; D001673:Biodegradation, Environmental; D002734:Chlorophyll / Q000378:metabolism; D000077194:Chlorophyll A; D017377:Diatoms / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D052244:Endocrine Disruptors / Q000378:metabolism* / Q000633:toxicity; D004958:Estradiol / Q000378:metabolism / Q000633:toxicity; D004997:Ethinyl Estradiol / Q000378:metabolism / Q000633:toxicity; D010636:Phenols / Q000378:metabolism / Q000633:toxicity; D012623:Seawater / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000378:metabolism* / Q000633:toxicity; D000098826:Bisphenol A Compounds
chemical_list: D001559:Benzhydryl Compounds; D002734:Chlorophyll; D000077194:Chlorophyll A; D052244:Endocrine Disruptors; D004958:Estradiol; D004997:Ethinyl Estradiol; D010636:Phenols; D014874:Water Pollutants, Chemical; C025256:nonylphenol; C006780:bisphenol A; D000098826:Bisphenol A Compounds