Production of Polygalacturonase by Aspergillus niger Cultured in the Medium Containing Mandarin Orange Peel

Abstract

Sixty-five strains of fungi were cultured in the liquid medium containing mandarin orange peel as a carbon source, and eight of them were chosen as effective producers of pectic enzymes. Especially, Aspergillus niger 35-1 was the most active in hydrolyzing mandarin orgnge peel. Production of pectic enzymes in the liquid culture of Asp. niger 35-1 and their characteristics were examined. Mandarin orange peel was found to be a favorable carbon source for the strain 35-1. Polygalacturonase (PG) activity was observed in 7 days of culture in shaking and maximum enzyme activity of PG reached 11.7 units per m1 of the culture medium. The optimum pH and temperature for the action of PG of this strain upon pectic acid were 2.5 to 4.0 and 55°C, respectively.