Behavior of Eu during culture of with yeast cells sorbing Eu

Kozai, Naofumi   ; Onuki, Toshihiko; Koka, Masashi; Sato, Takahiro; Kamiya, Tomihiro; Esaka, Fumitaka  

To reveal the role of protozoa in migration of radionuclides in the environment, this study investigated behavior of Eu during culture of () in media containing yeast on which Eu was sorbed. After the contact of yeast cells with a Eu(III) solution, many nano particles of Eu phosphate formed on yeast cells. cells were cultured with those yeast cells in an inorganic salt solution containing no phosphate. During the culture, the amount of the Eu leached into the aqueous phase was less than 0.1% of the Eu on the yeast cells. As culture time advances, membranous precipitates formed. These membranous precipitates contained undigested and digested yeast cells and dense membranous organic substance filling gaps between those cells. At the end of the culture, many nano particles of Eu phosphate were observed on digested residue of yeast cells. These results suggest that do not impair actinide-retardation action of microorganisms.