Bioaccumulation and chemical modification of Tc by soil bacteria

Journal Article · Tue Aug 01 04:00:00 EDT 1989 · Health Physics; (USA)

DOI:https://doi.org/10.1097/00004032-198908000-00001· OSTI ID:5257738

Henrot, J ^[1]

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1. Univ. of Tennessee, Knoxville (USA)

Bioaccumulation and chemical modification of pertechnetate (TcO{sub 4}-) by aerobically and anaerobically grown soil bacteria and by pure cultures of sulfate-reducing bacteria (Desulfovibrio sp.) were studied to gain insight on the possible mechanisms by which bacteria can affect the solubility of Tc in soil. Aerobically grown bacteria had no apparent effect on TcO{sub 4}-; they did not accumulate Tc nor modify its chemical form. Anaerobically grown bacteria exhibited high bioaccumulation and reduced TcO{sub 4}-, enabling its association with organics of the growth medium. Reduction was a metabolic process and not merely the result of reducing conditions in the growth medium. Association of Tc with bacterial polysaccharides was observed only in cultures of anaerobic bacteria. Sulfate-reducing bacteria efficiently removed Tc from solution and promoted its association with organics. Up to 70% of the total Tc in the growth medium was bioaccumulated and/or precipitated. The remaining Tc in soluble form was entirely associated with organics. Pertechnetate was not reduced by the same mechanism as dissimilatory sulfate reduction, but rather by some reducing agent released in the growth medium. A calculation of the amount of Tc that could be associated with the bacterial biomass present in soil demonstrates that high concentration ratios in cultures do not necessarily imply that bioaccumulation is an important mechanism for long-term retention of Tc in soil.

• OSTI ID: 5257738
• Journal Information: Health Physics; (USA), Journal Name: Health Physics; (USA) Vol. 57:2; ISSN 0017-9078; ISSN HLTPA
• Country of Publication: United States
• Language: English

Related Subjects

560162* -- Radionuclide Effects
Kinetics
& Toxicology-- Animals
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63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
BACTERIA
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIODEGRADATION
BIOLOGICAL ACCUMULATION
CARBOHYDRATES
CHEMICAL REACTIONS
DECOMPOSITION
HOURS LIVING RADIOISOTOPES
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MICROORGANISMS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PERTECHNETATES
POLYSACCHARIDES
RADIOISOTOPES
REFRACTORY METAL COMPOUNDS
SACCHARIDES
SOILS
SOLUBILITY
SULFATE-REDUCING BACTERIA
TECHNETIUM 99
TECHNETIUM COMPOUNDS
TECHNETIUM ISOTOPES
TRANSITION ELEMENT COMPOUNDS
YEARS LIVING RADIOISOTOPES