TY - JOUR T1 - Patterns of microbial sulfur isotope fractionation at low sulfate concentrations. JF - Geobiology Y1 - 2015 A1 - Bradley, AS. A1 - Leavitt, WD. A1 - Schmidt, M. A1 - Knoll, AH. A1 - Girguis, PR. A1 - Johnston, DT. ER -