Supporting Data for: Antimony Isotopic Fractionation during Microbial Reduction of Antimonate by Desulfuribacillus stibiiarsenatis MLFW-2

The data associated with the article "Antimony Isotopic Fractionation during Microbial Reduction of Antimonate by Desulfuribacillus stibiiarsenatis MLFW-2" by Hannah Veldhuizen, Thomas Johnson, Robert Sanford, and Thomas Kulp. The uploaded data file includes a table with Sb concentration and isotope data for all experiments and controls.

The redox reactions of antimony (Sb) play a big role in the mobility of Sb in the environment where Sb(V) is more mobile than Sb(III). Sb isotope ratio measurements (δ123Sb) can serve as an indicator of Sb redox reactions and immobilization. During reduction of Sb(V), the remaining reactant becomes enriched in the positive δ123Sb and the product becomes enriched in the negative δ123Sb. In this study we show that Sb(V) is reduced to Sb(III) by the microorganism, Desulfuribacillus stibiiarsenatis MLFW-2, by 59% to 85% over 96 hours. For this reaction, a kinetic isotope effect produces an isotopic fractionation (ε ≈ δinstantaneous product − δreactant) ranging from -1.05 ± 0.03‰ to -1.29 ± 0.18‰ (n=5, 2σ).