Sulphur isotope fractionation during the reduction of elemental sulphur and thiosulphate by Dethiosulfovibrio spp.
Stable sulphur isotope fractionation was investigated during reduction of thiosulphate and elemental sulphur at 28°C by growing batch cultures of the sulphur- and thiosulphate-reducing bacteria Dethiosulfovibrio marinus (type strain DSM 12537) and Dethiosulfovibrio russensis (type strain DSM 12538), using citrate as carbon and energy source. The cell-specific thiosulphate reduction rate in the growth phase was 7.4±3.9 fmol cell(-1) d(-1). The hydrogen sulphide produced was enriched in (32)S by 10.3±1 ‰ compared with total thiosulphate sulphur, close to previous experimental results observed for other sulphate- and non-sulphate-reducing bacteria. Elemental sulphur reduction yields sulphur isotope enrichment factors between-1.3 and-5.2 ‰ for D. russensis and-1.7 and-5.1 ‰ for D. marinus. The smaller fractionation effects are observed in the exponential growth phase (cellular rates between 5 and 70 fmol S° cell(-1) d(-1)) and enhanced discrimination under conditions of citrate depletion and cell lysis (cellular rates between 0.3 and 3 fmol S° cell(-1) d(-1)).
Max Planck Institute for Marine Microbiology, Bremen, Germany.
Alexander V
AV
Surkov
Michael E
ME
Böttcher
Jan
J
Kuever
D061249:Batch Cell Culture Techniques; D005591:Chemical Fractionation; D006089:Gram-Negative Anaerobic Bacteria / Q000378:metabolism*; D010084:Oxidation-Reduction; D013045:Species Specificity; D013455:Sulfur / Q000378:metabolism*; D013460:Sulfur Isotopes / Q000378:metabolism; D016999:Sulfur-Reducing Bacteria / Q000378:metabolism*; D013885:Thiosulfates / Q000378:metabolism*
D013460:Sulfur Isotopes; D013885:Thiosulfates; D013455:Sulfur