Molecular breeding of yeast with higher metal-adsorption capacity by expression of histidine-repeat insertion in the protein anchored to the cell wall.

A fusion protein of hexa-histidine repeat (His) and glycosylphosphatidylinositol (GPI)-anchor region of Saccharomyces cerevisiae Cwp1 with Aspergillus oryzae Taka-amylase A (TAA) was expressed on the yeast cell surface. The expressed fusion protein (TAA-His-Cwp1) was localized on the cell wall and demonstrated amylolytic activity. In comparison with the TAA-Cwp1 expressing strain, these cells exhibited 1.6- to 2.8-fold higher adsorbing capacity for Cu(2+), Ni(2+), and Zn(2+).