The goal of this research is to metabolically engineer yeast cells for the adsorption of heavy metal arsenic. The idea is to manipulate the transporter genes for both import and export of the ionic form of the heavy metal, as well as manipulating the reduction system inside the cell. The proposed work will also utilize an integration system that the co-principal investigator has developed in her laboratory. This integration method allows the sequential integration of multiple cloned genes. Advantages of this system include the ability to insert precise numbers of the same or different genes (important for metabolic engineering) and integration at dispersed chromosomal locations, improving the stability of the insertions. The initial cloning effort will allow for some characterization for subsequent development of optimal strains for hyper accumulation of arsenic.