title: Application of Freeze-Dried Powders of Genetically Engineered Microbial Strains as Adsorbents for Rare Earth Metal Ions.
abstract: The adsorption behaviors of the rare earth metal ions onto freeze-dried powders of genetically engineered microbial strains were compared. Cell powders obtained from four kinds of strains, Bacillus subtilis 168 wild type (WT), lipoteichoic acid-defective (ΔLTA), wall teichoic acid-defective (ΔWTA), and cell wall hydrolases-defective (EFKYOJLp) strains, were used as an adsorbent of the rare earth metal ions at pH 3. The adsorption ability of the rare earth metal ions was in the order of EFKYOJLp > WT > ΔLTA > ΔWTA. The order was the same as the order of the phosphorus quantity of the strains. This result indicates that the main adsorption sites for the ions are the phosphate groups and the teichoic acids, LTA and WTA, that contribute to the adsorption of the rare earth metal ions onto the cell walls. The contribution of WTA was clearly greater than that of LTA. Each microbial powder was added to a solution containing 16 kinds of rare earth metal ions, and the removals (%) of each rare earth metal ion were obtained. The scandium ion showed the highest removal (%), while that of the lanthanum ion was the lowest for all the microbial powders. Differences in the distribution coefficients between the kinds of lanthanide ions by the EFKYOJLp and ΔWTA powders were greater than those of the other strains. Therefore, the EFKYOJLp and ΔWTA powders could be applicable for the selective extraction of the lanthanide ions. The ΔLTA powder coagulated by mixing with a rare earth metal ion, although no sedimentation of the WT or ΔWTA powder with a rare earth metal ion was observed under the same conditions. The EFKYOJLp powder was also coagulated, but its flocculating activity was lower than that of ΔLTA. The ΔLTA and EFKYOJLp powders have a long shape compared to those of the WT or ΔWTA strain. The shapes of the cells will play an important role in the sedimentation of the microbial powders with rare earth metal ions. As the results, three kinds of the genetically engineered microbial powders revealed unique adsorption behaviors of the rare earth metal ions.
authors.affiliation: Faculty of Textile Science and Technology, Division of Applied Biology, Shinshu University , 3-15-1, Tokida, Ueda 386-8567, Japan.|Division of Instrumental Analysis (Ueda Branch), Research Center for Supports to Advanced Science, Shinshu University , 3-15-1, Tokida, Ueda 386-8567, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Moriwaki
authors.affiliation: Faculty of Textile Science and Technology, Division of Applied Biology, Shinshu University , 3-15-1, Tokida, Ueda 386-8567, Japan.
authors.forename: Reiko
authors.initials: R
authors.lastname: Masuda
authors.affiliation: Faculty of Textile Science and Technology, Division of Applied Biology, Shinshu University , 3-15-1, Tokida, Ueda 386-8567, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Yamazaki
authors.affiliation: Faculty of Textile Science and Technology, Division of Applied Biology, Shinshu University , 3-15-1, Tokida, Ueda 386-8567, Japan.
authors.forename: Kaoru
authors.initials: K
authors.lastname: Horiuchi
authors.affiliation: Faculty of Textile Science and Technology, Division of Applied Biology, Shinshu University , 3-15-1, Tokida, Ueda 386-8567, Japan.
authors.forename: Mari
authors.initials: M
authors.lastname: Miyashita
authors.affiliation: Faculty of Textile Science and Technology, Division of Applied Biology, Shinshu University , 3-15-1, Tokida, Ueda 386-8567, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Kasahara
authors.affiliation: Faculty of Textile Science and Technology, Division of Applied Biology, Shinshu University , 3-15-1, Tokida, Ueda 386-8567, Japan.
authors.forename: Tatsuhito
authors.initials: T
authors.lastname: Tanaka
authors.affiliation: Faculty of Textile Science and Technology, Division of Applied Biology, Shinshu University , 3-15-1, Tokida, Ueda 386-8567, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Yamamoto
mesh_terms: D000327:Adsorption; D005612:Freeze Drying; D007477:Ions; D008674:Metals, Rare Earth / Q000737:chemistry*; D011208:Powders
chemical_list: D007477:Ions; D008674:Metals, Rare Earth; D011208:Powders
keywords: Bacillus subtilis 168; adsorbent; genetically engineered strains; rare earth metal ions; teichoic acid