This microorganism can synthesize inorganic substances in the environment into organic substances it needs. This process requires specific enzymes, which participate in chemical reactions in microorganisms! Nitrifying bacteria, for example, can transform NO2 in the atmosphere into substances they need, use carbon dioxide as a carbon source, and use the energy released in the oxidation process of inorganic compounds such as ammonium, nitrite, hydrogen sulfide and iron ions to produce microorganisms that can grow. The main groups are sulfur bacteria, nitrifying bacteria and iron bacteria. Their growth needs to be carried out under aerobic conditions. Most methanogenic bacteria can survive by themselves. They grow with hydrogen as energy source and carbon dioxide as carbon source, and the product is methane. We call it anaerobic autotrophic fine nitrite bacteria (also known as ammonia-oxidizing bacteria), which oxidizes ammonia into nitrite. Nitrogen-containing bacteria (also known as nitrifying bacteria) oxidize nitrite into nitric acid, and use the energy released by oxidation to synthesize organic matter for their own use, that is, autotrophic microorganisms.

The number of bacteria is needed for one's own life activities …