Utilization of Agricultural Wastes by Aspergillus awamori for the Production of Glucoamylase

Abstract

The principal industrial use of glucoamylase is in the production of crystalline D-glucose. Aspergillus awamori was used. Variations in the specific type of carbohydrate source affected the yield of enzyme markedly. Of all the substrates tried, maltose supported satisfactory enzyme yields. Sucrose, lactose, fructose, and galactose gave abundant growth which seemed to be necessary but no sufficient condition for maximum yields. The specificity of the carbohydrate structure for glucoamylase production was tried. The synthesis of enzyme was significantly stimulated when two-third of the starch in the medium was replaced by maltose. The adaptation seemed to be specific to maltose structure, since the substitution of maltose by structurally related compounds, a.o. lactose, in the medium did not give a comparable glucoamylase yield. Maltose or compounds composed of maltose gave maximum yields of enzyme. These results seemed to favour the theory that glucoamylase production is adaptive. Agricultural wastes produced locally in large quantities from plants manufacturing starch and other products were discussed. Rice bran, followed by glucose syrup, corn bran, wheat bran, and cane sugar molasses supported good yields of glucoamylase.

Unterschiedliche Substrate verursachten unterschiedliche Grlukoamylasebildung durch Aspergillus awamori. Unter allen erprobten Substraten hat sich Maltose am besten bewährt. Andere Disaccharide sowie Stärke wirkten lange nicht so gut. Die adaptive Natur der Glukoamylasebildung läßt sich davon ableiten. Maltose oder stärkehaltige landwirtschaftliche Abfallprodukte lassen sich als Substrate für die industriemäßige Herstellung der Glukoamylase sinnvoll nutzen.