What is the role of sulfur chemoautotrophs in the sulfur cycle? Decomposition reduction oxidation assimilation Reduction of CO2 to generate carbohydrates can occur when coupled to the oxidation of reduced sulfur compounds (for examples, H2S). This latter process is carried out by what type of sulfate oxidizers sulfate reducers Solution 10 Oxidation Sulfur chemotrophs oxidize sufur to derive energy for the synthesis of ATP.