[The stimulating effect of N-nitroso-ethylurea on the biosynthetic ability of Aspergillus oryzae]

The mutagenic action of N-nitroso-N-ethylurea (NEU) taken at shock and prolonged doses together on Aspergillus oryzae yielded 98% of populations with an elevated synthesis of proteolytic enzymes. The combined action of shock and prolonged NEU doses had an advantage over a shock pulse dose because the frequency of mutations rose 2-16 times and the populations accumulated proteolytic enzymes within the range of 9 to 24 activity units. As was shown using a certain number of populations selected at random, the elevated accumulation of proteolytic enzymes in the medium remained stable within eight generations.