Defective life cycle and low antibiotic production in submerged cultures of Streptomyces fradiae.

The life cycle of a Streptomyces fradiae strain producing high amounts of neomycin under industrial conditions has been investigated in liquid soybean medium where the production of antibiotic proved to be comparatively low. The changes occurring in the main macromolecular components and the enzyme activities of the mycelium during the life cycle and cytological observations proved that there was a block in the normal proecess of reproductive differentiation and a lack of exocellular alkaline phosphatase activity was found.