Kinetics of the reduction of tetrathionate by intact bacterial cells

Капралек, Ф.; Pichinoty, F; Riegrová, J

doi:10.1007/bf02872792

Cited by 7 publications

(8 citation statements)

References 7 publications

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“…Tetrathionate reductase-2[H] + S4062-= 2S2032-+ 2H+ (66, 123, 124); Thiosulfate reductase-2[H] + S2032-= H2S + S032- (50,51,114). As the first reaction predicts, tetrathionate reduction results in significant acidification of the medium (66,69,123). In fact, typically, the reduction in vitro is linear for only a short period because the reductase loses activity as the pH falls (66,69,121).…”

Section: Reactions Under Considerationmentioning

confidence: 99%

“…As the first reaction predicts, tetrathionate reduction results in significant acidification of the medium (66,69,123). In fact, typically, the reduction in vitro is linear for only a short period because the reductase loses activity as the pH falls (66,69,121). Medium acidification during tetrathionate reduction is the basis of simple qualitative tests for the occurrence of this activity or its mutational loss in tetrathionate reducers (85).…”

Section: Reactions Under Considerationmentioning

confidence: 99%

“…Tetrathionate reductase has also been assayed by measuring hydrogen consumption in an assay mixture containing hydrogenase and benzyl viologen or methyl viologen as electron carrier (51,87,121) or by measuring benzyl viologen oxidation by tetrathionate (34). It is somewhat surprising that all of these 194 BARRETT AND CLARK assays, including titrations of thiosulfate, are possible in crude extracts of bacteria capable of thiosulfate reduction as well as tetrathionate reduction, but the investigators report that thiosulfate reduction in vitro does not begin until all tetrathionate has been reduced (66,124).…”

Section: Reactions Under Considerationmentioning

confidence: 99%

“…The enzyme has been partially purified from P. mirabilis and shown to have a molecular weight of 133,000 and two subunits of molecular weights 43,000'and 90,000 (112,113). The enzyme activity in C. freundii has been partially characterized (66,106,121). The Km for tetrathionate was 2 mM (121), and the pH optimum for tetrathionate reduction was 8.0 (66,105), with a 50% drop in activity when the pH drops below 7.2 (105).…”

Section: Tetrathionate and Thiosulfate Reduction By Enterobacteriaceaementioning

confidence: 99%

“…The enzyme activity in C. freundii has been partially characterized (66,106,121). The Km for tetrathionate was 2 mM (121), and the pH optimum for tetrathionate reduction was 8.0 (66,105), with a 50% drop in activity when the pH drops below 7.2 (105). This is somewhat surprising in light of the acidification that accompanies the reduction of tetrathionate to thiosulfate (66,69,123).…”

Section: Tetrathionate and Thiosulfate Reduction By Enterobacteriaceaementioning

confidence: 99%

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Tetrathionate reduction and production of hydrogen sulfide from thiosulfate.

Barrett¹,

Clark²

1987

Microbiological Reviews

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Section: Reactions Under Considerationmentioning

confidence: 99%

Section: Reactions Under Considerationmentioning

confidence: 99%

Section: Reactions Under Considerationmentioning

confidence: 99%

Section: Tetrathionate and Thiosulfate Reduction By Enterobacteriaceaementioning

confidence: 99%

Section: Tetrathionate and Thiosulfate Reduction By Enterobacteriaceaementioning

confidence: 99%

See 3 more Smart Citations

Tetrathionate reduction and production of hydrogen sulfide from thiosulfate.

Barrett¹,

Clark²

1987

Microbiological Reviews

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Reduction of tetrathionate, trithionate and thiosulphate, and oxidation of sulphide in Proteus mirabilis

Oltmann

Stouthamer

1975

Arch. Microbiol.

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The reductase catalyzing the reduction of tetrathionate and thiosulphate in Proteus mirabilis is also concerned with the reduction of trithionate and the oxidation of sulphide. Tetrathionate is reduced to thiosulphate, thiosulphate to sulphite and sulphide, and trithionate is reduced to thiosulphate plus sulphite. The oxidation of sulphide in cell-free extracts proceeds most likely to polysulphanes or to elemental sulphur, depending on the conditions. The kinetics of the reduction of tetrathionate imply a simultaneous interaction of tetrathionate and thiosulphate on the reductase molecule. The reduction of tetrathionate is activated by thiosulphate causing a non-linear progress of this reaction. On the other hand the reduction of thiosulphate is completely blocked until tetrathionate has been depleted. The order of reduction in a mixture of thiosulphate and trithionate is imputed by the enzymatic constants of the reductase for both substrates. Therefore in cell-free extracts thiosulphate is reduced prior to trithionate and afterwards, when thiosulphate has been exhausted, trithionate and the produced thiosulphate are reduced simultaneously. Fast growing cells, however, reduce trithionate first since their intracellular redox potential is insufficiently low to permit the reduction of any thiosulphate.

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Factors influencing the rate of electron transport in different respiratory pathways of bacteria

Капралек

Forman

1971

Folia Microbiol

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Kinetics of the reduction of tetrathionate by intact bacterial cells

Cited by 7 publications

References 7 publications

Tetrathionate reduction and production of hydrogen sulfide from thiosulfate.

Tetrathionate reduction and production of hydrogen sulfide from thiosulfate.

Reduction of tetrathionate, trithionate and thiosulphate, and oxidation of sulphide in Proteus mirabilis

Factors influencing the rate of electron transport in different respiratory pathways of bacteria

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