Radioactive yttrium isotopes (90Y and 91Y) are produced
during nuclear fission and are found in nuclear power plant waste effluents.
Consequently, research exploring microbial interactions with yttrium has focused on immobilization
of soluble yttrium via biosorption, bioaccumulation, and bioprecipitation.
90Y by bacteria (Schmidt and Dobberstein, 1957) and 91Y by
bacteria and protozoa (Morgan, 1961) has been demonstrated. Alcaligenes
eutrophus biofilms in flat membrane bioreactors were shown to precipitate yttrium and other
metals as insoluble carbonates (Van Roy et al, 1997). Pseudomonas
fluorescens grown with yttrium-complexed citrate as a sole carbon source accumulated
yttrium intracellularly in a phosphate-deficient medium (Appanna and Huang, 1992a), and deposited the metal in an insoluble extracellular
phosphate complex when grown in a phosphate-rich medium (Appanna and Huang, 1992b).
The majority of accumulated yttrium in P. fluorescens appeared to be associated with the
outer membrane (Appanna et al, 2001).
For more information:
Medline for yttrium metabolism AND bacteria
Appana VD, Huang J. Microbial precipitation of yttrium. Microbios.
Morgan GB. The absorbtion of radioisotopes by certain microorganisms. Quart J Fla
Acad Sci. 1961;24:94-100.
Schmidt B, Dobberstein H. The absorbtion of yttrium by bacteria.
Van Roy S, Peys K, Dresselaers T, Diels L. The use of an Alcaligenes
eutrophus biofilm in a membrane bioreactor for heavy metal recovery. Res