Azotobacter

The cells of bacteria of genus Azotobacter relatively large (1-2 microns in diameter), usually oval, but they have pleomorfizmom, ie can have different shapes - from bacillary to spherical. At the microscopic preparations of cells can be alone, in pairs, irregular clusters, or occasionally, chains of varying lengths. Form a distinct resting shape - cysts do not form spores.

In fresh cultures, the cells move through the multiple flagella. In later cultures, the cells lose their motility, become almost kokkovidnuyu form and produce a thick layer of mucus, which forms the capsule cells. At the cell shape also affects the chemical composition of nutrient medium - peptone, for example, is pleomorfizm, including, induces formation of so-called «gribopodobnyh» cells. Inducing effect on pleomorfizm in cultures of representatives of the genus azotobakter consisting of peptone provides amino acid glycine.

In microscopy, the cells are observed in the inclusions, some of which are painted, but some remains colorless. At the beginning of XX century it was believed that the inclusion of a prokrashivaemye «reproductive granules», or gonidiyami, and take part in the reproduction of cells, as a kind of «germ» cells, but then it was proved that the granules do not participate in the reproduction of cells and not are «small kokkopodobnymi reproductive cells» of bacteria - gonidiyami. Prokrashivaemye granules consist of volyutina, achromatophil same granules are drops of fat. Granules are the backup source of power.