BIOSYNTHESIS AND RELEASE OF ORGANOARSENIC COMPOUNDS BY MARINE-ALGAE

The uptake of arsenate from seawater, the biosynthesis of organoarsenic compounds, and the release of arsenite, methyl arsonate, and dimethyl arsinate have been studied in pure cultures of marine phytoplankton species, most of them bacteria free. Complex uptake kinetics and a wide variation in the degree of arsenic incorporation from the environment were found. In addition to a substantial amount of arsenic strongly bound to structural parts of the cell, up to 12 soluble organoarsenic compounds were formed by the algae. All species released substantial amounts of methyl arsonate and dimethyl arsinate into their environment. The production of arsenite was also common, and especially conspicuous with two species of coccolithophores. These findings explain at least in part the common occurrence of these arsenic compounds in the aquatic environment. © 1979, American Chemical Society. All rights reserved.