Addendum: Stable isotope fractionation by Clostridium pasteurianum. 3. Effect of on the physiology and associated sulfur isotope fractionation during and reductions

1981 ◽  
Vol 27 (2) ◽  
pp. 257-257
Author(s):  
G. I. Harrison ◽  
E. J. Laishley ◽  
H. R. Krouse
Keyword(s):  
Stable Isotope ◽  
Isotope Fractionation ◽  
Sulfur Isotope ◽  
Clostridium Pasteurianum ◽  
Stable Isotope Fractionation ◽  
Sulfur Isotope Fractionation

Stable isotope fractionation by Clostridium pasteurianum. 4. Sulfur isotope fractionation during enzymatic S3O62−, S2O32−, and SO32− reductions

1981 ◽  
Vol 27 (8) ◽  
pp. 824-834
Author(s):  
G. I. Harrison ◽  
E. J. Laishley ◽  
H. R. Krouse
Keyword(s):  
Stable Isotope ◽  
Isotope Fractionation ◽  
Sulfur Isotope ◽  
Isotope Effects ◽  
Growth Conditions ◽  
Enzyme Concentration ◽  
Clostridium Pasteurianum ◽  
Relative Reduction ◽  
Stable Isotope Fractionation ◽  
Sulfur Isotope Fractionation

Cell-free extracts from Clostridium pasteurianum grown on SO32− utilize H2 to reduce S3O62−, S2O32−, and SO32− to H2S at a much faster rate than extracts from SO42−-grown cells. This further supports the concept of an inducible dissimilatory type SO32− reductive pathway in this organism. 35S dilution experiments further support the concept that S3O62− and S2O32− are pathway intermediates. The inducible SO32− reductase is ferredoxin linked and the kinetics of the reduction and the sulfur isotope fractionation of the product can be altered by altering the growth conditions. The attending sulfur isotope fractionations are similar to those observed during the chemical decomposition of these compounds. In the case of S2O32−, 35S labelling experiments verified the conclusions derived from the stable isotope fractionation data concerning the relative reduction rates of the sulfane and sulfonate sulfurs. The reduction rates were also affected by enzyme concentration. The integrity of the whole cell is a necessary requirement for the large inverse isotope effects previously reported.

Stable isotope fractionation by Clostridium pasteurianum. 5. Effect of SeO42− on the physiology and associated sulfur isotope fractionation during SO32− and SO42− reductions

1982 ◽  
Vol 28 (3) ◽  
pp. 325-333 ◽  
Author(s):  
G. I. Harrison ◽  
E. J. Laishley ◽  
H. R. Krouse
Keyword(s):  
Stationary Phase ◽  
Isotope Fractionation ◽  
Sulfur Isotope ◽  
Reductase Activity ◽  
Clostridium Pasteurianum ◽  
Elemental Selenium ◽  
Whole Cells ◽  
Stable Isotope Fractionation ◽  
Sulfur Isotope Fractionation ◽  
Inverse Isotope Effect

The addition of 1 mM SeO42− significantly affected the physiology and metabolism of Clostridium pasteurianum growing on SO42− in the following ways: (1) the generation time was increased, essentially producing a biphasic growth curve, (2) cells became elongated and chains formed, (3) no H2S was liberated during the stationary phase, (4) assimilatory SO32− reductase activity was decreased, (5) ferredoxin levels decreased by a factor of 4. The effects of 1 mM SeO42− on Clostridium pasteurianum growing on SO32− were comparatively minor.H2S evolution in the stationary phase decreased by a factor of 2 and the δ34S maximum in the inverse isotope effect pattern occurred at a slightly lower percent H2S evolution. The deleterious effects of SeO42− addition were less pronounced than those associated with SeO32− addition. SeO32− but not SeO42− was reduced to elemental selenium by both whole cells and crude extracts.

Stable isotope fractionation by Clostridium pasteurianum. 2. Regulation of sulfite reductases by sulfur amino acids and their influence on sulfur isotope fractionation during SO32− and SO42− reduction

1978 ◽  
Vol 24 (6) ◽  
pp. 716-724 ◽  
Author(s):  
E. J. Laishley ◽  
H. R. Krouse
Keyword(s):  
Amino Acids ◽  
Isotope Fractionation ◽  
Sulfur Isotope ◽  
Sulfite Reductase ◽  
Clostridium Pasteurianum ◽  
Sulfur Amino Acids ◽  
Stable Isotope Fractionation ◽  
Sulfur Isotope Fractionation ◽  
Sulfide Production ◽  
Logarithmic Growth

In addition to an assimilatory sulfite reductase, studies of cultures of Clostridium pasteurianum supplemented with methionine, cysteine, and 35SO42− provide evidence for another reductase which is induced by SO32−. This inducible reductase appears to be dissimilatory because of the copious sulfide production arising when the cells are grown on SO32−. Cysteine can repress the assimilatory sulfite reductase but does not affect the inducible reductase. During late logarithmic growth on 1 mM SO42− + 10 mM cysteine, derepression of the inducible reductase occurred along with increased sulfide production. The presence of 1 mM cysteine and (or) 1 mM methionine does not affect the inverse sulfur isotope effect for evolved H2S. However, 5 and 10 mM cysteine reduce the maximum δ34S value for released H2S from +40 to +10‰. A small conversion of cysteine to H2S by C. pasteurianum occurs, but only in the stationary phase.

Thiosulfate formation and associated isotope effects during sulfite reduction by Clostridium pasteurianum

1979 ◽  
Vol 25 (6) ◽  
pp. 719-721 ◽  
Author(s):  
L. A. Chambers ◽  
P. A. Trudinger
Keyword(s):  
Isotope Fractionation ◽  
Sulfur Isotope ◽  
Isotope Effects ◽  
Clostridium Pasteurianum ◽  
Stages Of Growth ◽  
Bacterial Cultures ◽  
Sulfur Isotope Fractionation ◽  
Secondary Chemical Reaction ◽  
Secondary Chemical ◽  
Isotopic Effects

During growth of Clostridium pasteurianum on sulfite, approximately half the sulfite was reduced to sulfide and half to thiosulfate. Sulfide was enriched in 32S or 34S at different stages of growth and thiosulfate was enriched in 32S, particularly in the sulfane atom.It is suggested that thiosulfate in these bacterial cultures arose from a secondary chemical reaction. The chemical formation of thiosulfate from sulfide and sulfite was also accompanied by sulfur isotope fractionation. The implications of these results with respect to 'inverse' isotopic effects are discussed.

Stable isotope fractionation by Clostridium pasteurianum. 3. Effect of SeO32– on the physiology and associated sulfur isotope fractionation during SeO32– and SeO42– reductions

1980 ◽  
Vol 26 (8) ◽  
pp. 952-958 ◽  
Author(s):  
G. I. Harrison ◽  
E. J. Laishley ◽  
H. R. Krouse
Keyword(s):  
Isotope Fractionation ◽  
Chemical Mechanism ◽  
Clostridium Pasteurianum ◽  
Whole Cells ◽  
In Vivo Experiments ◽  
Stable Isotope Fractionation ◽  
Sulfur Isotope Fractionation ◽  
Generation Times

Increased [Formula: see text] concentration reduced H2S evolution from [Formula: see text] during whole cell and cell-free extract reductions by Clostridium pasteurianum. H2S production from [Formula: see text] was completely inhibited by [Formula: see text] in stationary phase cells. Generation times increased with greater [Formula: see text] concentration, the increase with 1 mM[Formula: see text] being a factor of 2.5 for 1 mM[Formula: see text], and over 3 for 1 mM[Formula: see text] reductions. In vitro and in vivo experiments with proposed intermediates of the [Formula: see text] reduction pathway show that [Formula: see text] inhibited both the [Formula: see text] to [Formula: see text] and [Formula: see text] to S2− reaction sequences with the latter being more pronounced in growth experiments. Both extracts and whole cells reduced [Formula: see text], to Se0 but Se0 granules were not found in the cell's cytoplasm. The formation of [Formula: see text] by an extracellular chemical mechanism appears not to have occurred in these experiments. Increased [Formula: see text] concentration had the effect of compressing the isotopic release pattern for H2S along the H2S production axis and did not significantly alter the maximum and mimimum values of δ34S. Thus, inhibition by [Formula: see text] limited the conversions of sulfur species without altering the isotopic selectivity of rate-controlling steps in the pathway.

SULFUR ISOTOPE FRACTIONATION IN BACTERIALLY AND CHEMICALLY CONTROLLED ROLL-FRONT DEPOSITS

2016 ◽  
Author(s):  
Gretchen Hough ◽  
◽  
Susan M. Swapp ◽  
Carol D. Frost
Keyword(s):  
Isotope Fractionation ◽  
Sulfur Isotope ◽  
Sulfur Isotope Fractionation

scholarly journals Unravelling the process of petroleum hydrocarbon biodegradation in different filter materials of constructed wetlands by stable isotope fractionation and labelling studies

2021 ◽  
Author(s):  
Andrea Watzinger ◽  
Melanie Hager ◽  
Thomas Reichenauer ◽  
Gerhard Soja ◽  
Paul Kinner
Keyword(s):  
Stable Isotope ◽  
Constructed Wetlands ◽  
Hydrogen Isotope ◽  
Petroleum Hydrocarbon ◽  
Isotope Fractionation ◽  
Isotope Effects ◽  
Filter Material ◽  
Hydrocarbon Biodegradation ◽  
Stable Isotope Fractionation ◽  
Filter Materials

AbstractMaintaining and supporting complete biodegradation during remediation of petroleum hydrocarbon contaminated groundwater in constructed wetlands is vital for the final destruction and removal of contaminants. We aimed to compare and gain insight into biodegradation and explore possible limitations in different filter materials (sand, sand amended with biochar, expanded clay). These filters were collected from constructed wetlands after two years of operation and batch experiments were conducted using two stable isotope techniques; (i) carbon isotope labelling of hexadecane and (ii) hydrogen isotope fractionation of decane. Both hydrocarbon compounds hexadecane and decane were biodegraded. The mineralization rate of hexadecane was higher in the sandy filter material (3.6 µg CO2 g−1 day−1) than in the expanded clay (1.0 µg CO2 g−1 day−1). The microbial community of the constructed wetland microcosms was dominated by Gram negative bacteria and fungi and was specific for the different filter materials while hexadecane was primarily anabolized by bacteria. Adsorption / desorption of petroleum hydrocarbons in expanded clay was observed, which might not hinder but delay biodegradation. Very few cases of hydrogen isotope fractionation were recorded in expanded clay and sand & biochar filters during decane biodegradation. In sand filters, decane was biodegraded more slowly and hydrogen isotope fractionation was visible. Still, the range of observed apparent kinetic hydrogen isotope effects (AKIEH = 1.072–1.500) and apparent decane biodegradation rates (k = − 0.017 to − 0.067 day−1) of the sand filter were low. To conclude, low biodegradation rates, small hydrogen isotope fractionation, zero order mineralization kinetics and lack of microbial biomass growth indicated that mass transfer controlled biodegradation.

Reactive transport modelling of porewater geochemistry and sulfur isotope fractionation in organic carbon amended mine tailings

2021 ◽  
pp. 104904
Author(s):  
Andrew T. Craig ◽  
Alexi Shkarupin ◽  
Richard T. Amos ◽  
Matthew B.J. Lindsay ◽  
David W. Blowes ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Mine Tailings ◽  
Reactive Transport ◽  
Isotope Fractionation ◽  
Sulfur Isotope ◽  
Reactive Transport Modelling ◽  
Transport Modelling ◽  
Sulfur Isotope Fractionation
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