THE PROTEOLYTIC ENZYMES OF MICROORGANISMS: II. FACTORS AFFECTING THE PRODUCTION OF PROTEASES IN SUBMERGED CULTURE

The main factors that influence the production of proteolytic enzymes by a few selected cultures have been studied. The time taken to reach the maximum yield of proteases is dependent upon the growth rate of each organism, and varies from two to five days. The fungi tested require the presence of an easily available carbohydrate source in addition to a protein substrate in order to produce high yields of proteolytic enzymes. The Streptomyces cultures will produce proteases in the absence of a carbohydrate source, but yields are generally low. The fungi studied will not produce significant amounts of proteases when grown on predominately inorganic nitrogen sources in contrast with the Streptomyces cultures, one of which produced almost as high yields of proteolytic enzymes when grown with sodium nitrate as when grown with Klim. Of a number of protein sources Klim and malt sprouts provided the best media for protease production. The temperature of incubation and pH of the culture medium are also important f...