Application of micro-PIXE technique to uptake study of cesium by

Onuki, Toshihiko; Sakamoto, Fuminori  ; Kozai, Naofumi   ; Ozaki, Takuo; Narumi, Issei; Francis, A. J.*; Iefuji, Haruyuki*; Sakai, Takuro; Kamiya, Tomihiro; Sato, Takahiro; Oikawa, Masakazu*

We examined the accumulation of Cs and Co, and the presence of other elements in yeast (Saccharomyces cerevisiae) cells by the particle induced X-ray emission (PIXE) system, which has low concentration detection limit of ppm, developed at the TIARA facility, JAERI, and by energy dispersive spectroscopy (EDS) equipped with scanning electron microscope. Addition of 1mM Cs did not have any effect on the growth of the yeast, whereas 0.5 mM Co inhibited its growth. Cells exposed to Cs showed an increase in Cs peak intensity, decrease in P, and no change in Fe, Zn and K with time. In the presence of Co, the intensity of Co and Fe peaks increased with time up to 21 hours while P, K and Zn exhibited no clear trend. These results suggest that PIXE is a useful technique to detect low concentration of elements in microbial cells as well as monitor their changes as function of growth.