[Antibiotic activity and heterogeneity of a population of Azotobacter chroococcum]

Antibiotic activity of Azotobacter chroococcum was determined depending on the morphological composition of the population. The population was divided by the sedimentary properties into 2 fractions: heavy (H) and light (L). A higher amount of azochroomycin (up to 170%) could be extracted from the H-fraction consisting mainly of medium size cells (1.3-1.9 nm in diameter) as compared to that from the L-fraction consisting predominantly of the cells of 0.7-1.3 nm in diameter; the activity of the L-fraction counted as 100%.