Aspergmus awamori NRRL 3112 was grown using the submerged technique in 10-liter laboratory fermenters during 7 days with continuous agitation and aeration of the nutrient. The activities of glucoamylase (GA) and α-amylase as well as changes in sugar and protein concentrations and pH were determined. Corn-bran fortified with potato starch proved to be the most favorable nutrient for glucoamylase synthesis.
The cultivation liquids of Asp. avamori strain NRRL 3112 of a highlevel glucoamylase production ability were processed in order to obtain concentrated enzyme preparations of a high activity and starch saccharification value. There have been obtained liquid preparations of a glucoamylase activity of about 9 500 u/g by direct concentration in a laboratory rotatory evaporator or at a semi-technical scale in a thin-layer evaporator Centri-therm, as well as by means of ultrafiltration. Those preparations kept stable during 6 months storage at 0-4°C. The solid preparations were obtained by means of salting out or alcohol precipitation; as compared with the initial or liquid preparations the farmer had an activity of up to 20 000 u/g and showed a higher DE value (up to 97.4 per cent). They were also shown to be stable during many months of storage.
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