Heavy metal uptake of Geosiphon pyriforme

Geosiphon pyriforme represents the only known endosymbiosis between a fungu s, belonging to the arbuscular mycorrhizal (AM) fungi, and cyanobacteria (b lue-green algae). Therefore we use Geosiphon as a model system for the wide spread AM symbiosis and try to answer some basic questions regarding heavy metal uptake or resistance of AM fungi. We present quantitative micro-PIXE measurements of a set of heavy metals (Cu, Cd, TI, Pb) taken up by Geosipho n-cells. The uptake is studied as a function of the metal concentration in the nutrient solution and of the time Geosiphon spent in the heavy metal en riched medium. The measured heavy metal concentrations range from several p pm to some hundred ppm. Also the influence of the heavy metal uptake on the nutrition transfer of other elements will be discussed. (C) 2001 Elsevier Science B.V. All rights reserved.