title: Uptake and biotransformation of arsenate in the lichen Hypogymnia physodes (L.) Nyl.
abstract: The uptake and metabolism of arsenate, As(V), as a function of time and concentration were examined in the lichen Hypogymnia physodes (L.) Nyl. Lichen thalli were exposed to As(V) in the form of a solution. Exponential uptake of As(V) from 4 microg mL(-1) As(V) solution was accompanied by constant arsenite, As(III), excretion back into the solution. Arsenate taken up into the lichens from 0, 0.1, 1, 10 microg mL(-1) As(V) solutions was partially transformed into As(III), dimethylarsinic acid (DMA) and (mono)methylarsonic acid (MA). 48 h after exposure, the main arsenic compound in the lichens was DMA in 0.1, As(III) in 1 and As(V) in 10 microg mL(-1) treatment. The proportion of methylated arsenic compounds decreased with increasing arsenate concentration in the exposure solution. These results suggest that at least two types of As(V) detoxification exist in lichens; arsenite excretion and methylation.
authors.affiliation: Department of Environmental Sciences, Jozef Stefan Institute, Jamova 39, Ljubljana, Slovenia.
authors.forename: Tanja
authors.initials: T
authors.lastname: Mrak
authors.forename: Zdenka
authors.initials: Z
authors.lastname: Slejkovec
authors.forename: Zvonka
authors.initials: Z
authors.lastname: Jeran
authors.forename: Radojko
authors.initials: R
authors.lastname: Jaćimović
authors.forename: Damijana
authors.initials: D
authors.lastname: Kastelec
mesh_terms: D001149:Arsenates / Q000493:pharmacokinetics*; D001152:Arsenicals / Q000378:metabolism; D018053:Arsenites / Q000378:metabolism; D001673:Biodegradation, Environmental; D018533:Biomass; D001711:Biotransformation; D002101:Cacodylic Acid / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D008011:Lichens / Q000378:metabolism*; D008745:Methylation; D011891:Rain; D013995:Time; D014874:Water Pollutants, Chemical / Q000493:pharmacokinetics*
chemical_list: D001149:Arsenates; D001152:Arsenicals; D018053:Arsenites; D014874:Water Pollutants, Chemical; D002101:Cacodylic Acid; C020300:monomethylarsonic acid; C015001:arsenite; C025657:arsenic acid