SI Fig. 5 Thiosulfat, Acetate, NO3- Benzoat, NO3- DMSO, S0, Taurine, O2 Control, Duplicate A Duplicate B Cells/ml Supplementary Figure 5. Growth test on various substrates of RCB from the sulfidic enrichment culture. Growth was monitored by counting the abundance of cells hybridized to probe ROS537 after two weeks of incubation. The aerobic control was not counted by FISH as no turbidity could be observed, whereas the taurine and DMSO treatments showed significant growth indicated by visible turbidity. Experiments were performed in duplicates. For substrate tests, 200 μl of the culture were anaerobically inoculated into 10 ml ASW medium in 20 ml hungate tubes that contained nitrate (5 mM). These were supplemented with either benzoate (2 mM), thiosulfate (5 mM), acetate (5 mM) or biogenic elemental sulfur, and incubated under a N2/CO2 (80/20 v/v) headspace. The biogenic sulfur was purified from cultures of Chlorobaculum parvum and kindly provided by C. Dona (University of Bremen). To test for growth with DMSO (5 mM) or taurine (5 mM) under aerobic conditions nitrate-free ASW medium was incubated with 10% of filter-sterilized air.