Isotope fractionation and sulfur metabolism by pure and enrichment cultures of elemental sulfur-disproportionating bacteria

摘要

ew have explored the sulfur metabolism and accompanying fractionation of sulfur isotopes during the dispro- portionation of elemental sulfur by seven different enrichments and three pure bacterial cultures. Cultures were obtained from both marine and freshwater environments. In all cases appreciable fractionation accompanied ele- mental sulfur disproportionation, with two ranges of fractionation observed. All cultures except Desulfobulbus propionicus produced sulfide depleted in ~34S by between 5.5 and 6.9 per mil (avg of 6.3 per ml) and sulfate enriched in ~34S by between 17.1 and 20.2 per mil (avg of 18.8 per ml).