The autolysis of Aspergillus flavus in an alkaline medium.

SUMMARY: The autolysis of Aspergillus flavus subjected to a combined action of a continuous flow of air and mechanical agitation has been studied. We have obtained a degree of autolysis amounting to 85%. The total loss of nitrogen in autolysing mycelium of A. flavus reached 82%, whereas the loss of phosphorus was 90% from the beginning of autolysis. Total carbohydrates were reduced from 524 mg./sample, at 0 day, to 119 mg./sample by the 16th day of autolysis, which represents a loss of 77%. Glucose was the only sugar found in significant amount in autolysing mycelium of A. flavus, being 96% the total loss. The concentration of mannitol decreased to nearly a third at the end of the log phase. The disappearance of this substance during pre-autolysis and autolysis amounted to 97.7% with respect to the maximum weight present at the 8th day of incubation. Fourteen different free amino acids were identified in the mycelium of Aspergillus flavus during the pre-autolytic and autolytic stages of growth. These amino acids increased their content between the 4th and the 6th days of incubation, to the highest concentration observed. Seventy-nine per cent of this maximum amount disappeared by the end of the log phase, whereas 78% of the remainder disappeared from mycelium during autolysis (16 days). From the total amount of bound amino acids in mycelium of A. flavus it seemed that the make-up of the mycelial protein does not undergo great changes in the interval between pre-autolysis and the initiation of the autolytic phase of growth.