Biomethylation and bioaccumulation of arsenic(V) by marine alga Fucus gardneri

The brown alga, Fucus gardneri, was collected from Vancouver Island, B,C,, Canada. Fucus samples were acclimated in seawater and then exposed to arsenic(V) in artificial seawater, all under axenic conditions. The arsenic species in the Fucus samples were extracted into 1:1 methanol-H2O and identified by using ion-pairing high-performance liquid chromatography coupled to inductively coupled plasma mass spectrometry (HPLC-ICP-MS), Anion-exchange HPLC-ICP-MS was used to identify the arsenic species in the growth medium. It was found that similar to 73% of the original arsenosugars in the F, gardneri samples were lost during the acclimation period. Arsenite [As(III)] and dimethylarsenate [DMA] concentration increased in the Fucus samples after exposure to arsenate [As(V)], A small increase in the concentration of an arsenosugar was seen during this period, accompanied by a further decrease in the concentration of two other arsenosugars. The experiments provided very little evidence for the hypothesis that arsenosugars are produced by the macroalgae. Copyright (C) 2001 John Wiley & Sons, Ltd.