Azotobacter

Representatives of the genus Azotobacter cyst is a resting form of vegetative cells required to experience the adverse factors of environment, and is not used for breeding. Following the resumption of optimal conditions, such as optimal pH, temperature and carbon source of income available to sprout cysts, newly formed vegetative cell reproduces by simple cell division. When germination of cysts ekzina cysts damaged, and released a large vegetative cell.

Microscopic manifestation of the first germination of the dispute is a gradual lowering of light refraction cyst with phase-contrast microscopy. Germination of cysts - a slow process and takes about 4-6 hours, during which the central body is increased and a seizure of granules volyutina mainly located in the intimate. Then ekzina burst and released from the vegetative cell ekziny with a characteristic horseshoe shape. In the germination of cysts observed metabolic changes. Immediately after adding the source of carbon to the environment cysts begin to absorb oxygen and to provide carbon dioxide, respiratory rate increased to maximum values at 4 hours after adding glucose. Synthesis of proteins and RNA to start after adding a source of carbon to the environment, but the intensification of synthesis of macromolecules marked by only 5 hours after adding the source of carbon. DNA synthesis and nitrogen fixation are initiated within 5 hours after adding glucose to the nutrient medium bezazotistoy.

During the germination of cysts observed changes in the intimate, visible on electron-microscopic preparations. Intima consists of carbohydrates, lipids and proteins and is almost the same amount in the cell as a central body. During the germination of cysts intima gidroliziruetsya and is used for the synthesis of cell components of the cell.