[Interaction mechanism between Zn(II) and Saccharomyces cerevisiae using EXAFS].

The extended X-ray absorption fine structure spectroscopy (EXAFS) was used to investigate the mechanisms of interaction between Zn(II) and Saccharomyces cerevisiae. The nature of the zinc center in the yeast cells exposed to different Zn(II) concentrations and initial pH was determined by Zn K-edge X-ray absorption spectroscopy. The experimental results suggested that the adsorbed zinc ion on the yeast was the mixture of tetrahedron and octahedron structure, and Zn-O bond length changed within 0.197-0.203 nm and coordination number varied between 4.3 and 3.2 under different conditions. Increase of the initial concentration of Zn(II) and initial pH value decreased the coordination number of Zn-O. Zn-O bond length and coordination number of the live cells of the yeast was lower than that of dead cells.