Proteolytic activity of subcellular fractions from Streptomyces griseus no. 45-H

Subcellular fractions were prepared from Streptomyces griseus No. 45-H at different stages of life cycle, and their proteolytic activity was examined. The highest proteolytic activity was found in the 24- and 72- h-old vegetative hyphae, the lowest in the resting spores. Spores contained about 9--30% of the proteolytic activity of vegetative cells. At the age of 16 h about 80%, at 26 h 70%, at 72 h 40%, and in spores about 60% of the proteolytic activity was particulate. The greatest part of the proteolytic activity could be inhibited by EDTA, lower levels of serine and sulfhydryl protease activities were detected in the cell-free extracts of vegetative cells.