Effect of glutathione on arsenic accumulation by dunaliella salina

The behavior of marine algae (Dunaliella salina, Chattonella antiqua, Heteresigma akashiwo, Skeletonema costatum, chaetoceros debile and Thalassiosira weissflogii) against arsenate, arsenite and DMA in a medium and the effects of glutathione that influenced the redox condition on arsenic accumulation of D. salina were studied. It was found that the order of growth inhibition of marine algae by arsenic species was As(III) > As(V) > DMA. The order of arsenic accumulation by D. salina was As(V) ≥ As(III) > DMA at a concentration of 100 mgAsdm^-3. A small part of the arsenic accumulated by D. salina was methylated in vivo. DMA was the major methylated arsenic compound. Methylated arsenic compounds were not present in the medium. Glutathione (GSH) treatment increased arsenic accumulation by D. salina at a concentration of 10-100 mg GSHdm^-3. Buthionine sulfoxisamine (a potent and specific inhibitor of γ-glutamylcysteine synthetase) strongly suppressed the effect of GSH on arsenic accumulation. These findings suggest that the intracellular glutathione concentration may be important for arsenic accumulation.