Enzymes of Aspergillus oryzae. I. The development of a culture medium yielding high protease activity.

When grown on modified Raulin's medium, containing additional sucrose, ammonium tartrate, and phosphate, Aspergillus oryzae yields more protease than when cultivated on unmodified Raulin's or Czapek-Dox media. Replacement of sucrose in the medium by fructose, invert sugar, glucose, maltose, starch, or lactose decreases the yield of enzyme in that order. Ammonium tartrate may be replaced by equivalent concentrations of the more readily available salts, sodium potassium tartrate (Rochelle salt) and ammonium chloride, without loss in activity.