Enhanced biosorption of cadmium ions on immobilized surface-engineered yeast using cadmium-binding peptides

A new type of cadmium (Cd) ion cell surface adsorbent was developed by integrating bacteriophage display peptide library technology with cell surface display technology. Cd²⁺ chelating resin served as the target molecule in screening experiments, leading to the identification of four Cd²⁺ -binding peptides. These peptides were introduced into <i>Saccharomyces cerevisiae</i> via the pYD1 plasmid using lithium acetate heat shock transformation. Adsorption efficiency tests indicated that the engineered yeasts adsorbed more Cd²⁺ than the control strain EBY100 when exposed to the same amount of Cd²⁺. Among these peptides, sequence 3-containing strain was demonstrated to have the highest Cd²⁺ adsorption efficiency, being 35% higher than the control strain. Additionally, when this recombinant yeast strain was immobilized using sodium alginate, the adsorption efficiency was increased by 55.7% compared to the control strain.