Sulfur Cycling Through Microbial Reactions

Sulfur cycling depends on microbial reactions that move sulfur through rocks, water, soil, and the air. In Earth systems, sulfur shifts among inorganic forms such as sulfate, elemental sulfur, and sulfide. These changes happen through both abiotic processes and biological activity in oxic and anoxic environments.

Inorganic sulfur cycles through the environment as sulfate, elemental sulfur, and sulfide.

Volcanoes and hydrothermal vents emit sulfur gases like hydrogen sulfide, making vital contributions to the sulfur cycle.

For example, in anoxic, organic-rich environments near hydrothermal vents, sulfate-reducing bacteria convert sulfate mainl...