Post-adsorption process of REE (Sm, Yb) phosphate nano-mineralization by microorganism

Jiang, M.; Onuki, Toshihiko; Tanaka, Kazuya*  ; Kozai, Naofumi   ; Kamiishi, Eigo; Utsunomiya, Satoshi*

The objective of the present study is to further understand the post-adsorption process of middle REE (Sm) and heavy REE (Yb) biomineralization by several representative microbes for the long-term exposure. Based on the FESEM and TEM analyses, nano-sized Sm phosphate crystallites with monazite structure formed on these three kinds of microbial cells surfaces and nano-sized Yb phosphate with amorphous phase formed on yeast cells surfaces. The EXAFS data indicated that the chemical states of accumulated Sm and Yb on cells surfaces changed from the mixture of both phosphate and carboxyl sites at 30 min to phosphate precipitates phase at 5 days, suggesting the REE-phosphate mineralization as a major post-adsorption process.