Uptake and Metabolism of DDT AND Dieldrin by Marine Algae

摘要

The uptake and metabolism of DDT and dieldrin of six species of marine phytoplankton was studied. Uptake of DDT by the various species increased linearly with an increasing concentration of DDT but non-linearly with an increasing concentration of cells. The species with higher numbers of cells per unit of mass took up greater amounts of DDT per unit weight than species with lower numbers of cells. All species concentrated DDT to levels many times higher than the original concentration in the medium. Maximum conversion of DDT to DDE was observed in cultures of Tetraselmis. In addition to DDE, Skeletonema also produced a small amount of an unknown polar metabolite from DDT. Six marine algae were found to remove dieldrin from the surrounding medium. The uptake of dieldrin increased linearly with an increasing concentration of the pesticide. With an increase in cell concentration, the amount of dieldrin accumulated by the cells increased linearly in Amphidinium but non-linearly in Isochrysis, Skeletonema, Tetraselmis, Olisthodiscus, and Cyclotella. None of the species was found to metabolize dieldrin. (Author)