STUDIES ON CARBON AND NITROGEN SOUCES FOR THE PRODUCTION OF AMYLOLYTIC ENZYMES BY SUBMERGED CULTURE OF ASPERGILLUS NIGER

Abstract

Aspergillus niger PRL 558 was used in the production of starch saccharifying enzymes. The culture was grown on 100 ml. of medium in 500 ml. Erlenmeyer flasks agitated and aerated on a rotary shaker at 35° C. Quantitative analyses for amylase, maltase, and limit dextrinase were determined on the culture filtrates. Variations in the specific type of carbohydrate source affected the yield of amylase markedly, and of maltase to a lesser extent. The production of limit dextrinase is the least dependent on the carbohydrate source. Maltose or compounds constituted of maltose units are essential for producing a maximum yield of amylase. The yields of the enzymes are related to the degree of the availability of the nitrogen source. Highest enzyme yields are obtained with hydrolyzed protein. However, the production of amylase and maltase is further stimulated by adding inorganic nitrogen compounds such as ammonium nitrate and sodium nitrate as a supplementary nitrogen source. The amounts of maltase and amylase obtained are controlled also by varying the fermentation time as well as the carbohudrate and protein content of the medium.