The use of stable sulfur isotope labelling to elucidate sulfur metabolism by Clostridium pasteurianum

1976 ◽  
Vol 109 (3) ◽  
pp. 315-317 ◽  
Author(s):  
Ronald G. L. McCready ◽  
Edward J. Laishley ◽  
H. Roy Krouse
Keyword(s):  
Sulfur Isotope ◽  
Sulfur Metabolism ◽  
Clostridium Pasteurianum ◽  
Isotope Labelling ◽  
Stable Sulfur Isotope

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 Sulfur Isotope Ratios: Source Indicators

1993 ◽  
pp. 183-183
Author(s):  
J. Calhoun ◽  
R. Delmas ◽  
H. Nielsen ◽  
G. Gravenhorst ◽  
J. Jouzel
Keyword(s):  
Sulfur Isotope ◽  
Isotope Ratios ◽  
Stable Sulfur Isotope

Stable sulfur isotope ratios as a tool for interpreting ecosystem sulfur dynamics

1986 ◽  
Vol 28 (1-2) ◽  
pp. 163-171
Author(s):  
R. D. Fuller ◽  
M. J. Mitchell ◽  
H. R. Krouse ◽  
B. J. Wyskowski ◽  
C. T. Driscoll
Keyword(s):  
Sulfur Isotope ◽  
Isotope Ratios ◽  
Stable Sulfur Isotope

The use of stable sulfur isotope ratio analysis to assess selectivity of chemical analyses and extractions of forms of sulfur in coal

Fuel ◽  
1994 ◽  
Vol 73 (10) ◽  
pp. 1578-1582 ◽  
Author(s):  
Simon H. Bottrell ◽  
Peter K.K. Louie ◽  
Ronald C. Timpe ◽  
Steven B. Hawthorne
Keyword(s):  
Isotope Ratio ◽  
Sulfur Isotope ◽  
Ratio Analysis ◽  
Chemical Analyses ◽  
Isotope Ratio Analysis ◽  
Sulfur In Coal ◽  
Stable Sulfur Isotope

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. 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.

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