Thermostable alkaline protease from Bacillus stearothermophilus F1; nutritional factors affecting protease production

The production of thermostable extracellular protease by Bacillus stearothermophilus F1 was influenced by the composition of culture medium. Peptone iv derived from soybean was the best organic compound for enzyme production. Sodium nitrate, ammonium salts and amino acids as sole nitrogen sources interfered with protease formation. The addition of most carbon sources to the peptone medium failed to improve the enzyme production. However, protease production was enhanced in the presence of melibiose and trehalose in sodium nitrate medium. Although the protease production was calcium independent, the presence of the metal ion at 4.5 mM enhanced the yield by two folds.