Studies on glucoamylase produced from Aspergillus awamori (NRRL-3112) and their effect on saccharification of potato starch.

Efficiency of an enzymatic starch saccharification process depends not only on the activity of the glucoamylase but also its purity. About 96.82% unwanted proteins present in 2-day old culture broth of A. awamori NRRL-3112 (grown in MYGP medium) were separated by precipitation with ammonium sulphate which was followed by dialysis. More than 80% activity of the glucoamylase was recovered. Three protein fractions (A, B, C) were identified using gel permeation chromatography. Fractions A and B showed comparatively higher glucoamylase activity than fraction-C. Moreover, fraction-B showed no product inhibition. The optimum temperature and pH of the purified enzyme (fraction-B) were 60 degrees C and 4.0 respectively. The saccharification efficiency of potato pulp was more in case of using purified glucoamylase (fraction-B) as compared to that of crude enzyme.