A microorganism that can oxidize inorganic substances and reduce carbon dioxide by using the generated chemical energy to generate organic carbides. There are not many kinds of chemotactic bacteria in nature, and the specificity of oxidized inorganic substances is very strong. For example, sulfate bacteria can only oxidize sulfur and hydrogen sulfide, nitrite bacteria can only oxidize ammonium salt, nitrate bacteria can only oxidize nitrite, hydrogen bacteria can only oxidize hydrogen, and iron bacteria can only oxidize ferrous salt. There are a considerable number of chemoautotrophic organisms in soil, which play a certain role in material transformation, especially in the process of weathering rocks into soil, and the pioneering role of autotrophic microorganisms can not be underestimated. There is also a photoautotrophic microorganism in nature, also known as photobacteria. They are similar to plants, contain bacteriocin, and can use light energy and carbon dioxide in the atmosphere to synthesize organic matter. The difference is that green plants use hydrogen produced by water photolysis to reduce carbon dioxide and release oxygen, while green sulfur bacteria obtain hydrogen from hydrogen sulfide and release sulfur.