Circulation of matter with energy in nature is the material basis of the overall dynamics of wildlife in nature, in which micro-organisms belonging to an unusually significant role. This natural process is necessary to ensure the concentration of certain elements in the biosphere to be able to meet the needs of wildlife and life in general. For example, if we imagine a world without the bacteria, it would be a world without diseases, without degradation of organic matter, and all the land would be covered with dead animals and plants that could not rot, because in a world without microbes would no longer be bacteria that are caring for a breakdown of all that is dead and thus create space for new organisms. All living beings needs a few dozens of biogenic elements and water. Some are needed in larger quantities such as macronutrients (carbon, nitrogen and oxygen), and others in smaller quantities are known as trace elements (phosphorus, sulfur). So circling atmospheric gases (oxygen, nitrogen, carbon dioxide), elements of rock or soil (phosphorus, sulfur, iodine). It is important to emphasize that any deviation from the normal value of any biogenic elements and its circulation in the biosphere disrupts normal development and functioning of a particular ecosystem. In this paper, a little more will be said about the cycling of nitrogen in nature and the role of microorganisms in that process.