FRACTIONATION OF SULFUR ISOTOPES DURING THIOSULFATE REDUCTION BY DESULFOVIBRIO-DESULFURICANS

Sulfur isotope fractionation during reduction of thiosulfate was inves tigated with growing batch cultures of Desulfovibrio desulfuricans CSN (DSM 9101) at 30 degrees C. The sulfide produced was depleted in S-34 by 10 parts per thousand as compared to total thiosulfate sulfur. The depletion was equal eo that during sulfate reduction under similar co nditions. The two sulfur atoms of the thiosulfate molecule were affect ed differently by fractionation, Sulfide produced from sulfonate sulfu r was depleted by 15.4 parts per thousand, sulfide produced from sulfa ne sulfur by 5.0 parts per thousand.