title: Glycosylation of bisphenol A by freshwater microalgae.
abstract: The endocrine disruptor bisphenol A (BPA, 4,4'-isopropylidenediphenol) is used to manufacture polycarbonate plastic and epoxy resin linings of food and beverage cans, and the residues from these products are then sometimes discharged into rivers and lakes in waste leachates. However, the fate of BPA in the environment has not yet been thoroughly elucidated. Considering the effect of BPA on aquatic organisms, it is important that we estimate the concentration of BPA and its metabolites in the aquatic environment, but there are few data on the metabolites of BPA. Here, we focused on freshwater microalgae as organisms that contribute to the biodegradation or biotransformation of BPA in aquatic environments. When we added BPA to cultures of eight species of freshwater microalgae, a reduction in the concentration of BPA in the culture medium was observed in all cultures. BPA was metabolized to BPA glycosides by Pseudokirchneriella subcapitata, Scenedesmus acutus, Scenedesmus quadricauda, and Coelastrum reticulatum, and these metabolites were then released into the culture medium. The metabolite from P. subcapitata, S. acutus, and C. reticulatum was identified by FAB-MS and (1)H-NMR as bisphenol A-mono-O-beta-d-glucopyranoside (BPAGlc), and another metabolite, from S. quadricauda, was identified as bisphenol A-mono-O-beta-d-galactopyranoside (BPAGal). These results demonstrate that freshwater microalgae that inhabit universal environments can metabolize BPA to its glycosides. Because BPA glycosides accumulate in plants and algae, and may be digested to BPA by beta-glycosidase in animal intestines, more attention should be given to levels of BPA glycosides in the environment to estimate the ecological impact of discharged BPA.
authors.affiliation: Environmental Biology Division, National Institute for Environmental Studies, Onogawa 16-2, Tsukuba, Ibaraki 305-8506, Japan. naka-320@nies.go.jp
authors.forename: Nobuyoshi
authors.initials: N
authors.lastname: Nakajima
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Teramoto
authors.forename: Fumie
authors.initials: F
authors.lastname: Kasai
authors.forename: Tomoharu
authors.initials: T
authors.lastname: Sano
authors.forename: Masanori
authors.initials: M
authors.lastname: Tamaoki
authors.forename: Mitsuko
authors.initials: M
authors.lastname: Aono
authors.forename: Akihiro
authors.initials: A
authors.lastname: Kubo
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kamada
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Azumi
authors.forename: Hikaru
authors.initials: H
authors.lastname: Saji
mesh_terms: D001559:Benzhydryl Compounds; D001711:Biotransformation; D052244:Endocrine Disruptors / Q000493:pharmacokinetics / Q000633:toxicity*; D056890:Eukaryota / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D020387:Food Chain; D005618:Fresh Water / Q000032:analysis / Q000382:microbiology; D006031:Glycosylation; D010636:Phenols / Q000493:pharmacokinetics / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000493:pharmacokinetics / Q000633:toxicity*; D000098826:Bisphenol A Compounds
chemical_list: D001559:Benzhydryl Compounds; D052244:Endocrine Disruptors; D010636:Phenols; D014874:Water Pollutants, Chemical; C006780:bisphenol A; D000098826:Bisphenol A Compounds