Americium is an α- and γ- emitting element that was first
discovered as a product of neutron capture reactions using plutonium
isotopes in a nuclear reactor. No biological role for americium is known.
Citrobacter sp. cells expressing surface phosphatase activity
could precipitate americium in phosphate complexes (Macaskie et al, 1994). Factors influencing americium
biosorption and bioaccumulation by bacteria (Wurtz et al, 1986; Francis et al, 1998) and fungi (Liu et al, 2002) have been investigated.
For more information:
Medline for americium AND bacteria
Francis AJ, Fillow JB, Dodge CJ, Dunn M, Mantione K, Strietelmeier BA,
Pansoy-Hjelvik ME, Papenguth HW. Role of bacteria as biocolloids
in the transport of actinides from a deep underground
radioactive waste repository. Radiochim Acta 1998;82:347-354.