The bioavailability of metals depends to a large extent on their chemical speciation in solution. Limits to the thermodynamic models most often used to predict trace metal bioavailability and toxicity have been identified and a chemodynamic approach has been put forward. In order to develop a more fundamental quantitative understanding of trace bioavailability, we are currently evaluating trace element transfer across the membranes of model microorganisms including Chlamydomonas reinhardtii. One aspect of this work involves quantifying the role of competition at transport sites on biouptake fluxes. We are also beginning to evaluate elemental fluxes for organisms embedded in solid matrices (gels, biofilms). Presently, we are especially interested in evaluating the risk of the rare earth metals and of metal mixtures.
Tan, Q.-G.; Yang, G.; Wilkinson, K. J.,
Biotic ligand model explains the effects of competition but not complexation for Sm biouptake by Chlamydomonas reinhardtii