Three polygalacturonases constitutively synthesized by Aspergillus alliaceus.

Of three molecular forms of polygalacturonases synthesized by Aspergillus alliaceus on glucose media, two were exopolygalacturonases (exoPG and exoPG) and one was an endopolygalacturonase (endoPG). Low-methoxylated beet pectin was the preferred substrate for the endoPG and exoPG whereas pectic acid was the optimal substrate for exoPG. The highest activities of endoPG, exoPG and exoPG were at pH 5.5, 3.5, and 6.0 and at 35, 45 to 50 and 35°C, respectively. Disks of potato-tuber tissue were macerated by endoPG, but not by exoPG or exoPG. [ABSTRACT FROM AUTHOR]