Sulfur bacteria can oxidize H2S and accumulate sulfur in the body. If H2S is lacking in the environment, the bacteria will oxidize sulfur in the body into sulfuric acid. The chemical reaction formula of this process is as follows:

2h2s+O2-2h2o+2s+ energy

2S+3O2S+3O2+2H2O-2H2SO4+energy

Sulfur bacteria use the energy released by the above two reactions to synthesize organic matter.

Iron bacteria is a kind of bacteria that can oxidize ferrous sulfate. The chemical reaction equation of this process is as follows:

4 ferrous sulfate +2h2so 4+O2-2fe 2(SO4)3+2H2O+ energy

Iron bacteria use the energy released by the above reaction to synthesize organic matter.

The above nitrifying bacteria, sulfur bacteria and iron bacteria are all aerobic bacteria.

Rhodosporium, also known as red non-sulfur bacteria, is an anaerobic autotrophic organism. It can not use sulfide as hydrogen donor, but can use hydrogen in some organic substances (such as fatty acids, alcohols, methane, etc. ) to reduce carbon dioxide and produce sugar. For example, there is a red yeast, CO2 is reduced by hydrogen of isopropanol to produce acetone and sugar, but oxygen is not released.