The researchers studied how organic sulfur compounds affect the sulfur cycle in a freshwater sediment. They found genes for sulfur reduction, oxidation, and organic sulfur compound degradation in Lake Superior sediment. Incubation experiments showed that microbes prefer sulfonates over sulfur-containing amino acids for sulfate production. Methyl-mercaptan degradation was also found to be active in the system. This research helps us understand how different sulfur compounds contribute to the sulfur cycle in low-sulfate environments.