Abstract
The paper described the results obtained in experiments on interspecific transformation in Azotobacter. When Azotobacter chroococcum was transformed with the DNA of A. vinelandii 6-10% of the colonies differed from the parent strain in colour, colony character and biochemical characteristics. Some of the trans-formant strains had higher nitrogen-fixing capacities than had the receptor strain. Transformants obtained by treatment of A. vinelandii with the DNA of A. chroococcum also had different colour, colony characteristics and capacity to grow in nutrient broth and peptone, but their nitrogen-fixing capacity was decreased,.