Optimisation of downstream processing parameters for the recovery of pectinase from the fermented bran of Aspergillus carbonarius

Aspergillus carbonarius produces extracellular pectinases when grown on wheat bran in solid-state fermentation (SSF) on a laboratory scale in flasks. The downstream processing parameters for recovery of the crude pectinases from the fermented bran were optimised. Optimum time and temperature of extraction were determined to be 15 min and 30 degrees C. The enzyme could be concentrated at least 4-fold in the extract by sequential extractions. Extraction using water or acetate buffer (pH 4.3) containing sodium sulphate resulted in maximum enzyme recovery. Colour and polysaccharides in the enzyme extract could be minimised by treatment with sodium chloride and activated charcoal. Concentration of the enzyme by ultrafiltration resulted in a 50-fold concentration of activity with 91% recovery. (C) 1999 Elsevier Science Ltd. All rights reserved.