Concentration of molybdenum by extra-cellular material produced by rhizosphere bacteria

Tan, Evan; Loutit, Margaret W.

doi:10.1016/0038-0717(76)90086-9

Cited by 12 publications

(2 citation statements)

References 16 publications

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“…Indeed, Tc complexes with polysaccharides such as starch have been synthesized under strongly reducing conditions (Paquette et al 1980), and CPS and EPS are known for their binding potential with metal ions (Tan and Loutit 1976;Mittelman and Geesey 1985;Martin et al 1975;Brown and Lester 1979). Indeed, Tc complexes with polysaccharides such as starch have been synthesized under strongly reducing conditions (Paquette et al 1980), and CPS and EPS are known for their binding potential with metal ions (Tan and Loutit 1976;Mittelman and Geesey 1985;Martin et al 1975;Brown and Lester 1979).…”

Section: Introduciionmentioning

confidence: 99%

Bioaccumulation and Chemical Modification of Tc by Soil Bacteria

Henrot¹

1989

Health Physics

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Bioaccumulation and chemical modification of pertechnetate (TcO4-) 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 TcO4-; they did not accumulate Tc nor modify its chemical form. Anaerobically grown bacteria exhibited high bioaccumulation and reduced TcO4-, 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.

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Section: Introduciionmentioning

confidence: 99%

Bioaccumulation and Chemical Modification of Tc by Soil Bacteria

Henrot¹

1989

Health Physics

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“…Also, it is postulated that soil organic matter may contain as much as 25 to 30% polysaccharide material which is of either microbial or plant origin (11). Seasonal changes in the degradation of microbial polysaccharides may influence soil aggregation and the uptake of essential metals by plants and may also affect plant mechanisms of detoxification from heavy metal contamination (3,16).…”

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confidence: 99%

Decomposition of Microbial Cell Components in a Semi-Arid Grassland Soil

Nakas

Klein

1979

Appl Environ Microbiol

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Cell component fractions ('4C-labeled) were prepared from bacterial and fungal cultures isolated from the Pawnee National Grassland in northeastern Colorado and tested for seasonal changes in degradability. The decomposition of cell component fractions was monitored from May to December of 1977 and during March of 1978, using soil samples taken at 2to 3-week intervals. The release of "CO2 from bacterial and fungal cell walls was inversely related (P < 0.01) to the soil moisture content. Except for cytoplasm isolated from an Aspergillus sp., all other cytoplasmic and polysaccharide fractions did not demonstrate a significant relationship between soil moisture and decomposability. In general, bacterial cell walls and polysaccharides were more susceptible to decomposition than fungal cell walls, although the seasonal changes in decomposability for both fractions were similar. These patterns of cell component utilization indicate that the decomposition of cell wall material may be more closely linked, on an inverse basis, to the availability of soil moisture and release of soluble, low-molecularweight organics resulting from primary production events.

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