Uptake and biotransformation of arsenate in the lichen Hypogymnia physodes (L.) Nyl

Environ Pollut. 2008 Jan;151(2):300-7. doi: 10.1016/j.envpol.2007.06.011. Epub 2007 Jul 19.

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.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arsenates / pharmacokinetics*
  • Arsenicals / metabolism
  • Arsenites / metabolism
  • Biodegradation, Environmental
  • Biomass
  • Biotransformation
  • Cacodylic Acid / metabolism
  • Chromatography, High Pressure Liquid
  • Lichens / metabolism*
  • Methylation
  • Rain
  • Time
  • Water Pollutants, Chemical / pharmacokinetics*

Substances

  • Arsenates
  • Arsenicals
  • Arsenites
  • Water Pollutants, Chemical
  • Cacodylic Acid
  • monomethylarsonic acid
  • arsenite
  • arsenic acid