Ans: Azotobacter is relatively large in size. The bacteria are generally oval in shape and may take various forms, such as rods and spheres. The colony morphology of azotobacter can be described as a glistening opaque white-colored mass with a flat and irregular shape. The growth is typically smooth and soft. The diameter of the colony is around 15mm. When we magnify by 10000 times, we can see that the cells of the azotobacter colony are bacilli and possess a negative Gram staining.