Radium is a highly radioactive element that occurs
naturally as a decay product of uranium and thorium. Exposure to radium has been linked to human cancers (ToxFAQs: Radium). Radium is found in highest
concentrations in uranium ores, and Ra+ can be mobilized from
uranium mine waste by the activity of sulfate-reducing (Landa et al, 1986) or iron(III)-reducing bacteria
(Landa et al, 1991). Some growing cyanobacteria and algae have been found to
accumulate radium (Havlik and Robertson, 1973), and biosorption of radium by
bacterial (Satvatmanesh et al, 2003) and fungal (Tsezos and Keller,
1983) biomass has been described.
For more information:
Medline for radium metabolism AND bacteria
Landa ER, Phillips JP, Loveley DR. Release of radium-226 from uranium
mill tailings by microbial iron3+ reduction. Appl Geochem.
Satvatmanesh DF, Siavoshi F, Beitollahi MM, Amidi J, Fallahian N. Biosorption
of 226 in high level natural radiation areas of Ramsar, Iran. J
Radioanal Nucl Chem. 2003;258:483-86.
Tsezos M, Keller DM. Adsorption of radium-226 by biological origin
absorbents. Biotechnol Bioeng. 1983;25:201-215.