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

ABSTRACT

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.