Transgenic

1. An isolated and purified transgenic Saccharomyces cerevisiae yeast cell comprising:

(a) a disrupted ACR3 gene of said yeast cell, wherein the disruption results in a reduction of heavy metal extrusion in the transgenic Saccharomyces cerevisiae yeast cell as compared to a corresponding wild-type Saccharomyces cerevisiae yeast cell; and

(b) a recombinant DNA sequence comprising a promoter operably linked to a nucleic acid molecule encoding yeast cadmium factor resistance protein Ycf1p, wherein the transgenic Saccharomyces cerevisiae yeast cell overexpresses Ycf1p as compared to a corresponding wild-type Saccharomyces cerevisiae yeast cell, such that the overexpression of Ycf1p and the reduction of heavy metal extrusion causes the transgenic Saccharomyces cerevisiae to have increased accumulation of at least one heavy metal from the cytosol into vacuoles relative to heavy metal accumulation from the cytosol into vacuoles in a corresponding Saccharomyces cerevisiae yeast cell with a disrupted ACR3 gene but not the recombinant DNA.

2. The trarisgenic Saccharomyces cerevisiae yeast cell of claim 1 wherein the ACR3 gene is disrupted by insertional inactivation.

3. The transgenic Saccharomyces cerevisiae yeast cell of claim 2 wherein the ACR3 gene is disrupted by homologous recombination of the ACR3 gene with a heterologous DNA sequence.

4. The transgenic Saccharomyces cerevisiae yeast cell of claim 1 wherein Ycf1p overexpression is inducible.

5. The transgenic Saccharomyces cerevisiae yeast cell of claim 1 wherein the heavy metal is selected from As(V), As(III), cadmium (Cd(II)), antimony (Sb (V), Sb(III)), mercury (Hg(II)), and lead (Pb(II)).

6. The transgenie Saccharomyces cerevisiae yeast cell of claim 5 , wherein the heavy metal is As(V) or As(III).

7. The transgenic Saccharomyces cerevisiae yeast cell of claim 1 further comprising an isolated DNA sequence comprising a promoter operably linked to a second nucleic acid molecule comprising an ACR2 gene.

8. The transgenic Saccharomyces cerevisiae yeast cell yeast of claim 7 wherein Acr2p is overexpressed from the ACR2 gene in the transgenic Saccharomyces cerevisiae yeast cell as compared to a wild-type Saccharomyces cerevisiae yeast cell such the reduction of As(V) to As(III) in the transgenic Saccharomyces cerevisiae yeast cell is not a rate limiting step in the detoxification of arsenic in the transgenic Saccharomyces cerevisiae yeast cell.

9. The transgenic Saccharomyces cerevisiae yeast cell of claim 1 , wherein the Acr3p disruption results in a reduction in As(III) extrusion.

10. The transgenic Saccharomyces cerevisiae yeast cell of claim 1 , further comprising a second recombinant DNA sequence comprising a promoter operably linked to a nucleic acid molecule encoding an aquaglyceroporin, wherein the transgenic Saccharomyces cerevisiae yeast cell expresses the aquaglyceroporin so as to cause the transgenic Saccharomyces cerevisiae yeast cell to have enhanced metalloid uptake from the aqueous medium relative to a corresponding cell without the second recombinant DNA sequence.

11. The transgenic Saccharomyces cerevisiae yeast cell of claim 10 , wherein the aquaglyceroporin is Fps1p, AQP7or AQP9.

12. The transgenic Saccharomyces cerevisiae yeast cell of claim 10 , wherein the aquaglyceroporin is Fps1p or AQP9.

13. A method for bioremediation of water contaminated with a heavy metal comprising:

(a) contacting the water with a population of yeast cells of claim 1 contained within a bioreactor, wherein the cells reduce the amount of heavy metal in the water; and

(b) monitoring the concentration of heavy metal in the water before and after the contact.

14. A bioreactor comprising a population of the yeast cells of claim 1 .

15. The transgenic Saccharomyces cerevisiae yeast cell of claim 1 , wherein the Acr3p disruption results in a reduction in arsenite extrusion.

16. The transgenic Saccharomyces cerevisiae yeast cell of claim 10 , wherein the aquaglycoporin is AQP9.

17. The method of claim 13 wherein the Acr3p disruption in the transgenic Saccharomyces cerevisiae results in a reduction in arsenite extrusion.

18. The method of claim 13 wherein the transgenic Saccharomyces cerevisiae yeast cell further comprises a second recombinant DNA sequence comprising a promoter operably linked to a nucleic acid molecule encoding an aquaglyceroporin, wherein the transgenic Saccharomyces cerevisiae yeast cell expresses the aquaglyceroporin so as to cause the transgenic Saccharomyces cerevisiae yeast cell to have enhanced metalloid uptake from the aqueous medium relative to a corresponding cell without the second recombinant DNA sequence.

19. The method of claim 18 wherein the aquaglyceroporin is Fps1p or AQP9.

20. The method of claim 13 wherein the heavy metal is selected from As(V), As(III), cadmium (Cd(II)), antimony (Sb (V), Sb(III)), mercury (Hg(II)), and lead (Pb(II)).

21. The method of claim 13 wherein the heavy metal is As(V) or As(III).